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Salerno S, Terranova MC, Vernuccio F, Picone D, Tudisca C, Lo Re G, Lagalla R. Imaging Assessment of Paediatric Crohn’s Disease: a Literature Review. Hong Kong J Radiol 2019. [DOI: 10.12809/hkjr1916912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
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2
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Re GL, Vernuccio F, Di Vittorio ML, Scopelliti L, Di Piazza A, Terranova MC, Picone D, Tudisca C, Salerno S. Swallowing evaluation with videofluoroscopy in the paediatric population. ACTA ACUST UNITED AC 2019; 39:279-288. [PMID: 30933173 PMCID: PMC6843585 DOI: 10.14639/0392-100x-1942] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 04/15/2018] [Indexed: 11/23/2022]
Affiliation(s)
- G Lo Re
- Section of Radiology Di.Bi.Med., University Hospital "Paolo Giaccone", Palermo, Italy
| | - F Vernuccio
- Section of Radiology Di.Bi.Med., University Hospital "Paolo Giaccone", Palermo, Italy
| | - M L Di Vittorio
- Section of Radiology Di.Bi.Med., University Hospital "Paolo Giaccone", Palermo, Italy
| | - L Scopelliti
- Section of Radiology Di.Bi.Med., University Hospital "Paolo Giaccone", Palermo, Italy
| | - A Di Piazza
- Section of Radiology Di.Bi.Med., University Hospital "Paolo Giaccone", Palermo, Italy
| | - M C Terranova
- Section of Radiology Di.Bi.Med., University Hospital "Paolo Giaccone", Palermo, Italy
| | - D Picone
- Section of Radiology Di.Bi.Med., University Hospital "Paolo Giaccone", Palermo, Italy
| | - C Tudisca
- Section of Radiology Di.Bi.Med., University Hospital "Paolo Giaccone", Palermo, Italy
| | - S Salerno
- Section of Radiology Di.Bi.Med., University Hospital "Paolo Giaccone", Palermo, Italy
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3
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Fonseca R, Palmer A, Picone D, Schultz M, Black A, Dwyer N, Roberts-Thomson P, Otahal P, Cremer A, Pucci G, Cheng H, Wang J, Schmieder R, Omboni S, Pereira T, Weber T, Bros W, Laugesen E, Westerhof B, Sharman J. Inaccurate Cuff-Blood Pressure Misses Potentially Preventable Cardiovascular Events and Increases Health Costs: a Markov Modelling Study from Real Patient Data. Heart Lung Circ 2019. [DOI: 10.1016/j.hlc.2019.06.050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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4
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Sandini M, Pinotti E, Persico I, Picone D, Bellelli G, Gianotti L. Systematic review and meta-analysis of frailty as a predictor of morbidity and mortality after major abdominal surgery. BJS Open 2017; 1:128-137. [PMID: 29951615 PMCID: PMC5989941 DOI: 10.1002/bjs5.22] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 09/14/2017] [Indexed: 12/21/2022] Open
Abstract
Background Frailty is associated with poor prognosis, but the multitude of definitions and scales of assessment makes the impact on outcomes difficult to assess. The aim of this study was to quantify the effect of frailty on postoperative morbidity and mortality, and long‐term mortality after major abdominal surgery, and to evaluate the performance of different frailty metrics. Methods An extended literature search was performed to retrieve all original articles investigating whether frailty could affect outcomes after elective major abdominal surgery in adult populations. All possible definitions of frailty were considered. A random‐effects meta‐analysis was carried out for all outcomes of interest. For postoperative morbidity and mortality, overall effect sizes were estimated as odds ratios (OR), whereas the hazard ratio (HR) was calculated for long‐term mortality. The potential effect of the number of domains of the frailty indices was explored through meta‐regression at moderator analysis. Results A total of 35 studies with 1 153 684 patients were analysed. Frailty was associated with a significantly increased risk of postoperative major morbidity (OR 2·56, 95 per cent c.i. 2·08 to 3·16), short‐term mortality (OR 5·77, 4·41 to 7·55) and long‐term mortality (HR 2·71, 1·63 to 4·49). All domains were significantly associated with the occurrence of postoperative major morbidity, with ORs ranging from 1·09 (1·00 to 1·18) for co‐morbidity to 2·52 (1·32 to 4·80) for sarcopenia. No moderator effect was observed according to the number of frailty components. Conclusion Regardless of the definition and combination of domains, frailty was significantly associated with an increased risk of postoperative morbidity and mortality after major abdominal surgery.
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Affiliation(s)
- M Sandini
- School of Medicine and Surgery, Milano-Bicocca University Monza Italy.,Department of Surgery San Gerardo Hospital Monza Italy
| | - E Pinotti
- School of Medicine and Surgery, Milano-Bicocca University Monza Italy.,Department of Surgery San Gerardo Hospital Monza Italy
| | - I Persico
- School of Medicine and Surgery, Milano-Bicocca University Monza Italy.,Department of Geriatrics Acute Geriatric Unit, San Gerardo Hospital Monza Italy
| | - D Picone
- School of Medicine and Surgery, Milano-Bicocca University Monza Italy.,Department of Geriatrics Acute Geriatric Unit, San Gerardo Hospital Monza Italy
| | - G Bellelli
- School of Medicine and Surgery, Milano-Bicocca University Monza Italy.,Department of Geriatrics Acute Geriatric Unit, San Gerardo Hospital Monza Italy
| | - L Gianotti
- School of Medicine and Surgery, Milano-Bicocca University Monza Italy.,Department of Surgery San Gerardo Hospital Monza Italy
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5
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Affiliation(s)
- R. Di Monaco
- Food Science and Agricultural Department; University of Naples Federico II; Portici Naples Italy
| | - N.A. Miele
- CAISIAL - Centre of Food Innovation and Development in the Food Industry; University of Naples Federico II; Via Università 100 Portici 80055 Naples Italy
| | - S. Volpe
- Food Science and Agricultural Department; University of Naples Federico II; Portici Naples Italy
| | - D. Picone
- Department of Chemical Sciences; University of Naples Federico II; Portici Naples Italy
| | - S. Cavella
- Food Science and Agricultural Department; University of Naples Federico II; Portici Naples Italy
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6
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Picone D, Climie R, Keske M, Sharman J. 2.6 NON-INVASIVE ESTIMATION OF EXERCISE CENTRAL BLOOD PRESSURE BY RADIAL TONOMETRY MAY BE UNDERESTIMATED DUE TO BRACHIAL-TO-RADIAL-SYSTOLIC-BLOOD-PRESSURE-AMPLIFICATION AND IS RELATED TO UPPER LIMB BLOOD FLOW VELOCITY. Artery Res 2014. [DOI: 10.1016/j.artres.2014.09.062] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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7
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Tuppo L, Alessandri C, Pomponi D, Picone D, Tamburrini M, Ferrara R, Petriccione M, Mangone I, Palazzo P, Liso M, Giangrieco I, Crescenzo R, Bernardi ML, Zennaro D, Helmer-Citterich M, Mari A, Ciardiello MA. Peamaclein - A new peach allergenic protein: similarities, differences and misleading features compared to Pru p 3. Clin Exp Allergy 2012; 43:128-40. [DOI: 10.1111/cea.12028] [Citation(s) in RCA: 69] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2012] [Revised: 09/13/2012] [Accepted: 09/18/2012] [Indexed: 01/16/2023]
Affiliation(s)
| | - C. Alessandri
- Center for Molecular Allergology; IDI-IRCCS; Rome; Italy
| | - D. Pomponi
- Center for Molecular Allergology; IDI-IRCCS; Rome; Italy
| | - D. Picone
- Department of Chemical Sciences; University Federico II of Naples; Naples; Italy
| | - M. Tamburrini
- Institute of Protein Biochemistry; CNR; Naples; Italy
| | - R. Ferrara
- Center for Molecular Allergology; IDI-IRCCS; Rome; Italy
| | - M. Petriccione
- Research Unit on Fruit Trees; Research Council for Experimentation in Agriculture; Caserta; Italy
| | - I. Mangone
- Centre for Molecular Bioinformatics, Department of Biology; University of Rome Tor Vergata; Rome; Italy
| | - P. Palazzo
- Center for Molecular Allergology; IDI-IRCCS; Rome; Italy
| | - M. Liso
- Center for Molecular Allergology; IDI-IRCCS; Rome; Italy
| | | | | | - M. L. Bernardi
- Center for Molecular Allergology; IDI-IRCCS; Rome; Italy
| | - D. Zennaro
- Center for Molecular Allergology; IDI-IRCCS; Rome; Italy
| | - M. Helmer-Citterich
- Centre for Molecular Bioinformatics, Department of Biology; University of Rome Tor Vergata; Rome; Italy
| | - A. Mari
- Center for Molecular Allergology; IDI-IRCCS; Rome; Italy
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8
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Affiliation(s)
- R. Di Monaco
- Food Science Department; University of Naples; Via Università 100 80055 Portici (NA) Italy
- Centre for Food Innovation and Development; University of Naples; Portici Italy
| | - N.A. Miele
- Food Science Department; University of Naples; Via Università 100 80055 Portici (NA) Italy
| | - D. Picone
- Department of Chemical Sciences; University of Naples; Portici Italy
| | - P. Masi
- Food Science Department; University of Naples; Via Università 100 80055 Portici (NA) Italy
- Centre for Food Innovation and Development; University of Naples; Portici Italy
| | - S. Cavella
- Food Science Department; University of Naples; Via Università 100 80055 Portici (NA) Italy
- Centre for Food Innovation and Development; University of Naples; Portici Italy
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9
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Bernardi ML, Picone D, Tuppo L, Giangrieco I, Petrella G, Palazzo P, Ferrara R, Tamburrini M, Mari A, Ciardiello MA. Physico-chemical features of the environment affect the protein conformation and the immunoglobulin E reactivity of kiwellin (Act d 5). Clin Exp Allergy 2010; 40:1819-26. [PMID: 20825426 DOI: 10.1111/j.1365-2222.2010.03603.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
BACKGROUND Allergy diagnostic systems sometimes give false positive or negative results. In this respect, the influence of protein conformational changes on the allergen-IgE interaction sites is worthy to be investigated. OBJECTIVE To investigate the influence of different experimental conditions on the structural properties and IgE reactivity of kiwellin (Act d 5) as a model system. METHODS Act d 5 was purified from the natural source. To study its conformational features, experiments of circular dichroism (CD) in different media were performed. The IgE reactivity was investigated by skin testing, immunoblotting and ISAC microarray system, in a population of kiwifruit allergic subjects. RESULTS CD experiments indicated that Act d 5 has a mainly helical structure and the conformation is strongly affected by the experimental conditions. The protein is more structured in low polarity media and at acidic pH values, similar to those of the natural source. Eleven subjects of 29 (38%) allergic to kiwifruit were positive to purified natural Act d 5 by skin test. Among them, three patients (10%) showed a reaction only to Act d 5 at pH 4.5, and three (10%) showed a reaction only to the allergen in standard neutral conditions. No one of the 11 subjects with positive skin test recognized Act d 5 immobilized on the ISAC system. Eight of nine subjects detected Act d 5 by IgE immunoblotting. One subject did not recognize the sequence epitopes of Act d 5 in IgE immunoblotting experiments and reacted to the skin test only when the allergen was in acidic conditions. CONCLUSIONS AND CLINICAL RELEVANCE The conformation and IgE reactivity of Act d 5 are affected by the physico-chemical characteristics of the solvent. These findings suggest that the assay conditions influence the results of the diagnostic systems by modulating the pattern of exposed antigenic epitopes.
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Affiliation(s)
- M L Bernardi
- Center for Molecular Allergology, IDI-IRCCS, Roma, Italy
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10
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Sica F, Picone D, Merlino A, Di Fiore A, Ercole C, Franzese M, Mazzarella L. Hinge peptide and intersubunit interface in domain swapping. Acta Crystallogr A 2005. [DOI: 10.1107/s010876730508983x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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11
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Picone D, Crescenzi O, Angeli S, Marchese S, Brandazza A, Ferrara L, Pelosi P, Scaloni A. Bacterial expression and conformational analysis of a chemosensory protein from Schistocerca gregaria. Eur J Biochem 2001; 268:4794-801. [PMID: 11532016 DOI: 10.1046/j.1432-1327.2001.02408.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Chemosensory proteins (CSPs) are a class of small, soluble proteins present at high concentrations in chemosensory organs of different insect species. Several pieces of evidence suggest their involvement in carrying chemical messages from the environment to chemosensory receptors. However, a structural description of the mechanism of delivery has not been reported. In order to provide the first detailed conformational characterization of these molecules, we cloned a specific isoform (CSP-sg4) from Schistocerca gregaria and expressed it in Escherichia coli. The product was obtained with yields of more than 20 mg per L of culture, all in its soluble form. The recombinant protein was identical to the native one with respect to pairing of the disulfide bridges, aggregative state and secondary structure elements. Structural investigations revealed a significantly stable polypeptide with respect to variations in temperature and acidity. CD analysis, preliminary NMR data and secondary structure prediction pointed to a correctly folded structure where helical regions and loops are alternated in a similar fashion as that observed for other classes of odorant- and pheromone-binding proteins presenting no sequence similarity to CSPs.
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Affiliation(s)
- D Picone
- Dipartimento di Chimica, Universita' Federico II, Napoli, Italy
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12
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Crescenzi O, Carotenuto A, D'Ursi AM, Tancredi T, D'Alessio G, Avitabile F, Picone D. 1H and 15N sequential assignment and secondary structure of the monomeric N67D mutant of bovine seminal ribonuclease. J Biomol NMR 2001; 20:289-290. [PMID: 11519752 DOI: 10.1023/a:1011294812364] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
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13
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Picone D, Rivieccio A, Crescenzi O, Caliendo G, Santagada V, Perissutti E, Spisani S, Traniello S, Temussi PA. Peptide T revisited: conformational mimicry of epitopes of anti-HIV proteins. J Pept Sci 2001; 7:197-207. [PMID: 11354463 DOI: 10.1002/psc.320] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Peptide T (ASTTTNYT), a fragment corresponding to residues 185-192 of gp120, the coat protein of HIV, is endowed with several biological properties in vitro, notably inhibition of the binding of both isolated gp120 and HIV-1 to the CD4 receptor, and chemotactic activity. Based on previous nuclear magnetic resonance (NMR) studies performed in our laboratory, which were consistent with a regular conformation of the C-terminal pentapeptide, and SAR studies showing that the C-terminal pentapeptide retains most of the biological properties, we designed eight hexapeptides containing in the central part either the TNYT or the TTNY sequence, and charged residues (D/E/R) at the two ends. Conformational analysis based on NMR and torsion angle dynamics showed that all peptides assume folded conformations. albeit with different geometries and stabilities. In particular, peptides carrying an acidic residue at the N-terminus and a basic residue at the C-terminus are characterized by stable helical structures and retain full chemotactic activity. The solution conformation of peptide ETNYTR displays strong structural similarity to the region 19-26 of both bovine pancreatic and bovine seminal ribonuclease, which are endowed with anti-HIV activity. Moreover, the frequent occurrence, in many viral proteins, of TNYT and TTNY, the two core sequences employed in the design of the hexapeptides studied in the present work, hints that the sequence of the C-terminal pentapeptide TTNYT is probably representative of a widespread viral recognition motif.
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Affiliation(s)
- D Picone
- Dipartimento di Chimica, Università degli Studi di Napoli Federico II, Complesso Universitario di Monte S. Angelo, Italy.
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14
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Abstract
Nocistatin, a new heptadecapeptide encoded in the bPNP-3 gene, has a powerful biological activity connected with the mechanisms of pain transmission. It does not bind to the opioid receptors but to another brain receptor with high affinity. In order to substantiate these novel biological data with a structural basis, we have undertaken a conformational study in solution. Proton nmr data in helicogenic solvents are consistent with a well-defined helical structure that is consistent with the nmr parameters of the C-terminal octapeptide, a shorter fragment that retains allodynia-blocking activity.
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Affiliation(s)
- O Crescenzi
- Dipartimento di Chimica, Università di Napoli Federico II, via Mezzocannone 4, I-80134 Napoli, Italy
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15
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Abstract
Beta-endorphin is the largest natural opioid peptide. The knowledge of its bioactive conformation might be very important for the indirect mapping of the active site of opioid receptors. We have studied beta-endorphin in a variety of solution conditions with the goal of testing the intrinsic tendency of its sequence to assume a regular fold. We ran NMR experiments in water, dimethylsulfoxide and aqueous mixtures of methanol, ethylene glycol, trifluoroethanol, hexafluoracetone trihydrate and dimethylsulfoxide. The solvent in which the peptide is more ordered is the hexafluoracetone trihydrate/water mixture. The helical structure detected for beta-endorphin in this mixture at 300 K extends for the greater part of its address domain, hinting at a possible mechanism of interaction with opioid receptors: a two-point attachment involving an interaction of the helical part of the address domain (PLVTLFKNAIIKNAY) with one of the transmembrane helices and a classical interaction of the message domain (YGGF) with the receptor subsite common to all opioid receptors.
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Affiliation(s)
- G Saviano
- Università del Molise, Isernia, Italy
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16
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Abstract
Dynorphin A, the endogenous agonist for the kappa opioid receptor, has been studied by NMR spectroscopy in methanol, acetonitrile, DMSO and in mixtures of hexafluoroacetone/water and DMSO/water. NMR data in the DMSO/water cryomixture at 278 K are consistent with a conformer in which the N-terminal part, like the corresponding message domain of enkephalins, is poorly ordered, whereas the C-terminal part is folded in a loop centred around Pro10. The folded structure of the C-terminal part (address moiety) may shed light on the role of the essential residues Arg7, Lys11 and Lys13.
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17
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Abstract
Conformational studies of enkephalins are hampered by their high flexibility which leads to mixtures of quasi-isoenergetic conformers in solution and makes NOEs very difficult to detect in NMR spectra. In order to improve the quality of the NMR data, Leu-enkephalin was synthesized with 15N-labelled uniformly on all amide nitrogens and examined in a viscous solvent medium at low temperature. HMQC NOESY spectra of the labelled Leu-enkephalin in a DMSOd6/H2O) mixture at 275 K do show numerous NOEs, but these are not consistent with a single conformer and are only sufficient to describe the conformational state as a mixture of several conformers. Here a different approach to the structure-activity relationships of enkephalins is presented: it is possible to analyse the NMR data in terms of limiting canonical structures (i.e. beta- and gamma-turns) and finally to select only those consistent with the requirements of delta selective agonists and antagonists. This strategy results in the prediction of a family of conformers that may be useful in the design of new delta selective opioid peptides.
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Affiliation(s)
- P Amodeo
- Istituto Chimica Molecole di Interesse Biologico (associated to the Italian National Institute for the Chemistry of Biological Systems), CNR, Arco Felice, Italy
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18
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Crescenzi O, Fraternali F, Picone D, Tancredi T, Balboni G, Guerrini R, Lazarus LH, Salvadori S, Temussi PA. Design and solution structure of a partially rigid opioid antagonist lacking the basic center--models of antagonism. Eur J Biochem 1997; 247:66-73. [PMID: 9249010 DOI: 10.1111/j.1432-1033.1997.t01-1-00066.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
To discriminate between two general models of antagonism (participation and allosteric), an opioid antagonist lacking the basic nitrogen of tyramine was designed and characterized. Cyclo-[Tyr(Me)2-Tic-], the diketopiperazine of 2,6-dimethyltyrosyl-1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid, is a partially rigid opioid antagonist; its pA2 (5.8) is one smaller than that of N,N-bisallyl-enkephalin but it has a very high binding affinity (10 nM) and has a delta selectivity (66 with respect to the binding to mu receptors) higher than that of naltrindole. The conformational state of this diketopiperazine, studied under a variety of solvent and temperature conditions by NMR and molecular dynamics, can be described in terms of only three conformers whose relative populations vary widely with solvent. Only one of the three conformers, characterized by a 90 degree arrangement of the aromatic rings of Tyr(Me)2 and Tic similar to those of rigid agonists and of the bioactive conformation of the corresponding linear antagonist, is consistent with the antagonist activity. This finding favors the participation model among the general mechanisms proposed to explain antagonism. Due to the simple composition of the conformational mixture and to the rigidity of the molecule, it is possible to propose a quantitative explanation for the discrepancy between the very high binding affinity (10 nM) and the fairly small in mouse vas deferens value (1.5 microM).
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Affiliation(s)
- O Crescenzi
- Dipartimento di Chimica, Università di Napoli Federico II, Italy
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19
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Salvadori S, Picone D, Tancredi T, Guerrini R, Spadaccini R, Lazarus LH, Regoli D, Temussi PA. Solution conformation of nociceptin. Biochem Biophys Res Commun 1997; 233:640-3. [PMID: 9168905 DOI: 10.1006/bbrc.1997.6285] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Nociceptin, a novel heptadecapeptide, interacts with ORL1 a G protein-coupled receptor whose sequence is closely related to that of the kappa opioid receptor but has no opioid activity. We have investigated the conformational preferences of Nociceptin also in comparison to Dynorphin A. The N-terminal part of Nociceptin has the same conformational preferences of the message of endogenous opioids but the C-terminal part of the sequence is more flexible than the corresponding address of Dynorphin A. [Tyr1]-Nociceptin, while retaining nociceptive activity, has also an opioid activity comparable to that of enkephalins.
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Affiliation(s)
- S Salvadori
- Dipartimento di Scienze Farmaceutiche, Università di Ferrara, Italy
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20
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Crescenzi O, Amodeo P, Cavicchioni G, Guerrini R, Picone D, Salvadori S, Tancredi T, Temussi PA. Delta-selective opioid peptides containing a single aromatic residue in the message domain: an NMR conformational analysis. J Pept Sci 1996; 2:290-308. [PMID: 9230457 DOI: 10.1002/psc.56] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The sequence of deltorphin I, a delta-selective opioid agonist, has been systematically modified by inserting conformationally constrained C alpha, alpha disubstituted apolar residues in the third position. As expected, substitution of Phe with Ac6c, Ac5c and Ac3c yields analogues with decreasing but sizeable affinity. Surprisingly, substitution with Aib yields an analogue with almost the same binding affinity of the parent compound but with a greatly increased selectivity. This is the first case of a potent and very selective opioid peptide containing a single aromatic residue in the message domain, that is, only Tyr1. Here we report a detailed conformational analysis of [Aib3]deltorphin I and [Ac6c3]deltorphin I in DMSO at room temperature and in a DMSO/water cryomixture at low temperature, based on NMR spectroscopy and energy calculations. The peptides are highly structured in both solvents, as indicated by the exceptional finding of a nearly zero temperature coefficient of Val5 NH resonance. NMR data cannot be explained on the basis of a single structure but it was possible to interpret all NMR data on the basis of a few structural families. The conformational averaging was analysed by means of an original computer program that yields qualitative and quantitative composition of the mixture. Comparison of the preferred solution conformation with two rigid delta-selective agonists shows that the shapes of [Aib3]deltorphin I and [Ac6c3]deltorphin I are consistent with those of rigid agonists and that the message domain of opioid peptides can be defined only in conformational terms.
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Affiliation(s)
- O Crescenzi
- Dipartimento di Chimica, Università di Napoli Federico II, Italy
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21
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Tuzi A, Ciajolo MR, Picone D, Crescenzi O, Temussi PA, Fissi A, Pieroni O. 3(10)-Helices, helix screw sense and screw sense reversal in the dehydro-peptide Boc-Val-delta Phe-Gly-delta Phe-Val-OMe. J Pept Sci 1996; 2:47-58. [PMID: 9225245 DOI: 10.1002/psc.47] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The pentapeptide Boc-Val-delta Phe-Gly-delta Phe-Val-OME, containing two dehydro-phenylalanine (delta Phe) residues, has been synthesized and its structure investigated. In the crystalline state, the molecule adopts a right-handed 3(10)-helical conformation stabilized by two intramolecular hydrogen bonds between CO of Val1 and NH of delta Phe4, and between CO of delta Phe2 and NH of Val5, respectively. NMR measurements are consistent with the presence of 3(10)-helical structures also in acetonitrile and dimethylsulphoxide solution: the distances between backbone protons estimated from NOE connectivities are in overall agreement with those observed in the solid state; the chemical shifts of the amide protons show the smaller temperature coefficients for the NHs that in solid state are involved in intramolecular hydrogen bonds. The CD spectra in acetonitrile, chloroform, methanol and dimethylsulphoxide display exciton couplets of bands corresponding to the delta Phe electronic transition at 280 nm; the sign of the bands is consistent with the presence of helical structures having a prevalent left-handed screw sense. Addition of 1,1,1,3,3,3-hexafluoro-propan-2-ol gives rise to the gradual appearance of a couplet of opposite sign, suggesting the helix reversal from left-handed sense to right-handed sense. The conformational behaviour is discussed on the basis of the specific sequence of the peptide.
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Affiliation(s)
- A Tuzi
- Department of Chemistry, University of Naples, Italy
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Amodeo P, Balboni G, Crescenzi O, Guerrini R, Picone D, Salvadori S, Tancredi T, Temussi PA. Conformational analysis of potent and very selective delta opioid dipeptide antagonists. FEBS Lett 1995; 377:363-7. [PMID: 8549756 DOI: 10.1016/0014-5793(95)01374-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The delta selectivity and antagonism of peptides containing L-tetrahydro-3-isoquinoline carboxylic acid (Tic) in second position can be attributed mainly to the Tyr-Tic unit. These properties can be further enhanced by substituting Tyr1 with 2,6-dimethyl-L-tyrosyl (Dmt). Dmt-Tic-NH2, Dmt-Tic-OH, Dmt-Tic-Ala-NH2 and Dmt-Tic-Ala-OH are all more active and/or selective than the corresponding [Tyr1]-parent peptides. In fact the selectivities of Dmt-Tic-OH and Dmt-Tic-Ala-OH are the highest ever recorded for opioid molecules. 1H NMR spectra in a DMSO/water mixture at 278 K reveal the presence of two similar conformers, characterised by a cis or trans Dmt-Tic bond, in all four peptides. A detailed conformational analysis in solution of Dmt-Tic-NH2 shows that these conformers have a shape very similar to that of the bioactive conformation of Tyr-Tic-NH2 and to that of naltrindole.
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Affiliation(s)
- P Amodeo
- ICMIB del CNR, Arco Felice, Napoli, Italy
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23
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Salvadori S, Attila M, Balboni G, Bianchi C, Bryant SD, Crescenzi O, Guerrini R, Picone D, Tancredi T, Temussi PA. Delta opioidmimetic antagonists: prototypes for designing a new generation of ultraselective opioid peptides. Mol Med 1995; 1:678-89. [PMID: 8529134 PMCID: PMC2229973] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Tyr-Tic (1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid) and Tyr-Tic-Ala were the first peptides with delta opioid antagonist activity lacking Phe, considered essential for opioid activity based on the N-terminal tripeptide sequence (Tyr-D-Xaa-Phe) of amphibian skin opioids. Analogs were then designed to restrain the rotational flexibility of Tyr by the substitution of 2,6-dimethyl-L-tyrosine (Dmt). MATERIALS AND METHODS Tyr and Dmt peptides were synthesized by solid phase and solution methods using Fmoc technology or condensing Boc-Dmt-OH or Boc-Tyr(But)-OH with H-L-Tic-OBut or H-D-Tic-OBut, respectively. Peptides were purified (> 99%) by HPLC and characteristics determined by 1H-NMR, FAB-MS, melting point, TLC, and amino acid analyses. RESULTS H-Dmt-Tic-OH had high affinity (Ki delta = 0.022 nM) and extraordinary selectivity (Ki mu/Ki delta = 150,000); H-Dmt-Tic-Ala-OH had a Ki delta = 0.29 nM and delta selectivity = 20,000. Affinity and selectivity increased 8700- and 1000-fold relative to H-Tyr-Tic-OH, respectively. H-Dmt-Tic-OH and H-Dmt-Tic-NH2 fitted one-site receptor binding models (eta = 0.939-0.987), while H-Dmt-Tic-ol, H-Dmt-Tic-Ala-OH and H-Dmt-Tic-Ala-NH2 best fitted two-site models (eta = 0.708-0.801, F 18.9-26.0, p < 0.0001). Amidation increased mu affinity by 10- to 100-fold and acted synergistically with D-Tic2 to reverse selectivity (delta-->mu). Dmt-Tic di- and tripeptides exhibited delta antagonist bioactivity (Ke = 4-66 nM) with mouse vas deferens and lacked agonist mu activity (> 10 microM) in guinea-pig ileum preparations. Dmt-Tic analogs weakly interacted with kappa receptors in the 1 to > 20 microM range. CONCLUSIONS Dmt-Tic opioidmimetic peptides represent a highly potent class of opioid peptide antagonists with greater potency than the nonopioid delta antagonist naltrindole and have potential application as clinical and therapeutic compounds.
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Affiliation(s)
- S Salvadori
- Department of Pharmaceutical Sciences, University of Ferrara, Italy
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24
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Ciajolo MR, Balboni G, Picone D, Salvadori S, Tancredi T, Temussi PA, Tuzi A. Solution and solid-state structure of the diketopiperazine of tyrosyl-tetrahydroisoquinoline-3-carboxylic acid. Int J Pept Protein Res 1995; 46:134-8. [PMID: 8567167 DOI: 10.1111/j.1399-3011.1995.tb01328.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
delta-Selective antagonism of [L-Tic2]-peptides, including the simple dipeptide Tyr-L-Tic-NH2, is linked to the Tyr-Tic-"recognition site". In order to gain further information on the conformational preferences of the Tyr-Tic-moiety we have undertaken a structural study of a cyclic analog, the diketopiperazine of Tyr-Tic. A conformational study of cyclo[-Tyr-Tic-], that is almost devoid of opioid activity, can also be useful to discriminate between the role of the two aromatic rings and of the basic nitrogen in determining antagonism. The structure of cyclo[-Tyr-Tic-] has been solved in a DMSO/water solution at 278 K by NMR spectroscopy and in the solid state by X-ray diffraction methods. The two informations are almost identical, with an arrangement of the aromatic rings rather different from that of the putative bioactive conformation of the parent linear dipeptide. This difference points to the importance of conformational effects and is in agreement with the hypothesis that the positive center may be not essential for antagonism.
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Affiliation(s)
- M R Ciajolo
- Department of Chemistry, University of Naples Federico II, Italy
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25
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D'Ursi A, Oschkinat H, Cieslar C, Picone D, D'Alessio G, Amodeo P, Temussi PA. Assignment and secondary-structure determination of monomeric bovine seminal ribonuclease employing computer-assisted evaluation of homonuclear three-dimensional 1H-NMR spectra. Eur J Biochem 1995; 229:494-502. [PMID: 7744072 DOI: 10.1111/j.1432-1033.1995.tb20490.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Monomeric bovine seminal ribonuclease (mBS-RNase), the subunit of dimeric bovine seminal ribonuclease (BS-RNase), is an unusual monomer: for its structural stability, its catalytic activity, which is even higher than that of the parent dimeric enzyme, and for its role as an intermediate in the refolding of dimeric BS-RNase. Here we present the proton NMR assignment and secondary-structure determination of mBS-RNase, with a comparison of its structure to the structure of its parent protein, and to the structure of RNase A, a homologue with more than 80% identity in amino acid sequence. Proton NMR assignment was performed using a computer-assisted procedure, through a partially automated analysis of homonuclear three-dimensional spectra [Oschkinat, H., Holak, T. A. & Cieslar, C. (1991) Biopolymers 31, 699-712]. The secondary structures of mBS-RNase, of the A chain of dimeric BS-RNase, and of RNase A, are found to be similar. Significant differences are found instead, between mBS-RNase and RNase A in the more flexible stretches of the molecule, where a higher number of substitutions is present. Furthermore, a preliminary tertiary-structure model is reported, showing that the overall folding of mBS-RNase is closer to that of RNase A rather than that of (dimeric) BS-RNase.
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Affiliation(s)
- A D'Ursi
- Dipartimento di Chimica, Università di Napoli Federico II, Italy
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26
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Tancredi T, Salvadori S, Amodeo P, Picone D, Lazarus LH, Bryant SD, Guerrini R, Marzola G, Temussi PA. Conversion of enkephalin and dermorphin into delta-selective opioid antagonists by single-residue substitution. Eur J Biochem 1994; 224:241-7. [PMID: 8076645 DOI: 10.1111/j.1432-1033.1994.tb20017.x] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The properties of di- and tri-peptides containing 1,2,3,4-tetrahydroisoquinoline-3-carboxylic acid (Tic) in second position suggest that the message domain of opioid peptides can be composed of only two residues [Temussi, P. A., Salvadori, S., Amodeo, P., Guerrini, R., Tomatis, R., Lazarus, L. H., Picone, D. & Tancredi, T. (1994) Biochem. Biophys. Res. Commun. 198, 933-939]. As a crucial test of the possibility that the Tyr-Tic segment be a message domain in longer peptide sequences, we have inserted it in the sequences of two typical opioid peptides: [Leu]enkephalin, a non-selective agonist, and dermorphin, a selective mu agonist. Here we report the synthesis and biological activity of [L-Tic2]enkephalin, [L-Tic2]dermorphin, [L-Tic2]dermorphin carboxylic acid and [D-Tic2]dermorphin: all [L-Tic2]peptides were converted from agonists to delta-selective antagonists. The NMR conformational study in a dimethylsulfoxide/water cryoprotective mixture at low temperature shows diagnostic side-chain--side-chain NOEs in the spectra of all [L-Tic2]peptides and hints that the 90 degrees arrangement of the the two aromatic rings found in the cis-Tyr-L-Tic moiety, typical of N-methyl naltrindole and other delta-selective opiate antagonists, is responsible for the antagonist activity of all these peptides.
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27
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Temussi PA, Salvadori S, Amodeo P, Bianchi C, Guerrini R, Tomatis R, Lazarus LH, Picone D, Tancredi T. Selective opioid dipeptides. Biochem Biophys Res Commun 1994; 198:933-9. [PMID: 8117299 DOI: 10.1006/bbrc.1994.1133] [Citation(s) in RCA: 79] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The surprising change of selectivity induced by the change of chirality in peptides containing the tetrahydro-3-isoquinoline carboxylic acid (Tic) in second position, interpreted as a conformational preference induced on the Tyr-Xaa-Phe domain, can instead be attributed to the Tyr-Tic message domain. The relative spatial disposition of the aromatic ring of delta-selective non peptidic opiates is compatible with a message domain, in opioid peptides, of only two residues. This hypothesis was tested through the synthesis of Tyr-L-Tic-NH2, Tyr-D-Tic-NH2, Tyr-L-Tic-Ala-NH2, Tyr-L-Tic-Ala-OH and Tyr-D-Tic-Ala-NH2. Peptides containing Tyr-L-Tic- behave as very selective delta antagonists and those containing Tyr-DTic- as non selective agonists. This is the first case of opioid peptides containing a two-residue message domain and of opioid dipeptides with substantial opioid activity.
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MESH Headings
- Amino Acid Sequence
- Animals
- Binding, Competitive
- Brain/metabolism
- Cell Membrane/metabolism
- Dipeptides/chemical synthesis
- Dipeptides/chemistry
- Dipeptides/pharmacology
- Enkephalin, Ala(2)-MePhe(4)-Gly(5)-
- Enkephalin, D-Penicillamine (2,5)-
- Enkephalins/metabolism
- Enkephalins/pharmacology
- Guinea Pigs
- Ileum/drug effects
- Ileum/physiology
- In Vitro Techniques
- Isoquinolines
- Kinetics
- Models, Molecular
- Molecular Sequence Data
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Muscle, Smooth/physiology
- Narcotics/chemical synthesis
- Narcotics/chemistry
- Narcotics/pharmacology
- Oligopeptides/pharmacology
- Protein Conformation
- Radioligand Assay
- Rats
- Receptors, Opioid, delta/metabolism
- Receptors, Opioid, mu/metabolism
- Stereoisomerism
- Structure-Activity Relationship
- Synaptosomes/metabolism
- Tetrahydroisoquinolines
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Affiliation(s)
- P A Temussi
- Dipartimento di Chimica, Università di Napoli Federico II, Italy
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28
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Abstract
Casokefamide (Tyr-D-Ala-Phe-D-Ala-Tyr-NH2) is a synthetic peptide derived from the beta-casomorphin sequence, designed to increase the resistance to gastric proteases. Casokefamide binds to both mu and delta-opioid receptors, while beta-casomorphins and its fragments are typical mu-opioid receptor agonists. Furthermore, casokefamide can affect gastric acid and pancreatic exocrine secretions and also gastrointestinal motility. We have undertaken a conformational study on this peptide based on NMR measurements in a DMSOd6/H2O cryomixture at 265 K and energy calculations. The predominant conformation is characterised by the absence of regular structures and intramolecular hydrogen bonds. The conformation of the message domain is reminiscent of the shape of several peptidic and non peptidic opiates, with the D-Ala2CH3 group sandwiched between Tyr1 and Phe3 aromatic rings.
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Affiliation(s)
- V Brantl
- Pharma Bissendorf Peptide GmbH, Hannover, Germany
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29
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Abstract
Cholecystokinin (CCK) is a peptide hormone endowed with several important biological activities, both in the central and peripheral nervous system. Previous conformational studies have dealt mainly with its C-terminal octapeptide fragment (CCK8), which represents the shortest fully circulating form of this hormone. We have undertaken a detailed NMR conformational study in a DMSOd6/H2O cryomixture at 278 K of the CCK analog H-Arg-Asp-Tyr(SO3H)-Thr-Gly-Trp-Nle-Asp-PheNH2 (CCK9) which retains all the bioactivities of CCK8, but was found to be remarkably more stable in acidic media and unaffected by air oxidation due to Met replacements. The predominant conformation contains a gamma-turn centered on Thr4, separated by Gly5 from a helical segment that comprises the C-terminal residues.
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Affiliation(s)
- L Moroder
- MPI für Biochemie, Martinsried bei München, Germany
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30
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31
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Temussi PA, Picone D, Saviano G, Amodeo P, Motta A, Tancredi T, Salvadori S, Tomatis R. Conformational analysis of an opioid peptide in solvent media that mimic cytoplasm viscosity. Biopolymers 1992; 32:367-72. [PMID: 1623132 DOI: 10.1002/bip.360320412] [Citation(s) in RCA: 30] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Many neuropeptides exert their action between the presynaptic vesicles and postsynaptic transmembrane receptors, crossing different layers of specialized cytoplasm. Biomimetic media usually employed to study bioactive peptides do not reproduce the physico chemical environment of cytoplasm--in particular, the high viscosity of this biological fluid. Here we describe a conformational study of a delta-selective opioid peptide, deltorphin I, at variable temperatures in several biocompatible media characterized by varying values of viscosity and dielectric constant. It was found that only viscosity, among these parameters, induces ordered conformations; that is, it acts as a conformational sieve. This finding suggests that the high viscosity of the intersynaptic fluid contributes, in addition to the membrane catalysis proposed by Schwyzer, in overcoming the so-called entropic barrier to the transition state of peptide-receptor interaction by selecting ordered conformations prior to receptor interaction. The folded conformer found in the 80:20 (v:v) DMSOd6/H2O cryoprotective mixture at 265 K has a shape consistent with those of rigid nonpeptidic opiates.
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Affiliation(s)
- P A Temussi
- Dipartimento di Chimica, Università degli Studi di Napoli Federico II, Italy
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32
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Amodeo P, Motta A, Tancredi T, Salvadori S, Tomatis R, Picone D, Saviano G, Temussi PA. Solution structure of deltorphin I at 265 K: a quantitative NMR study. Pept Res 1992; 5:48-55. [PMID: 1623303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Deltorphin I, a delta-selective opioid peptide, has been studied in a DMSOd6/H2O cryoprotective mixture by two-dimensional (2D) NMR spectroscopy in the temperature range 260 K to 305 K. The high viscosity of the solvent at low temperature mimics a distinctive physico-chemical feature of cytoplasm and allows the measurement of a NOESY spectrum rich in intra- and inter-residue effects. Backbone NOEs at 265 K can be calculated with good accuracy in terms of only two limiting conformers: one folded, with a mole fraction of 0.30, and another extended with a mole fraction of 0.70. This calculation is still a rough approximation of the complex conformational equilibria existing in solution but, to the best of our knowledge, is the first one for a flexible peptide, and represents an encouraging starting point for a quantitative evaluation of NMR data of small, flexible peptides in solution. The folded conformer consistent with observed NOEs has a shape surprisingly similar to those of unrelated, rigid, delta-selective opiates.
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Affiliation(s)
- P Amodeo
- Istituto Chimica M.I.B del CNR, Arco Felice, Italy
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33
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Tancredi T, Temussi PA, Picone D, Amodeo P, Tomatis R, Salvadori S, Marastoni M, Santagada V, Balboni G. New insights on mu/delta selectivity of opioid peptides: conformational analysis of deltorphin analogues. Biopolymers 1991; 31:751-60. [PMID: 1932571 DOI: 10.1002/bip.360310620] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The message domain of dermorphin (Tyr-D-Ala-Phe), a natural mu-opioid heptapeptide, has long been considered the main cause of the high mu selectivity of this peptide and of its analogues. The recent discovery, in the skin of Phyllomedusa sauvagei (i.e., the same natural source of dermorphin) and of Phyllomedusa bicolor of deltorphins, challenges this belief. Deltorphins, in fact, are three heptapeptides characterized by a message domain typical of mu-selective peptides, but endowed of an extremely high delta selectivity, the highest of all natural opioid peptides. A conformational analysis of dermorphin and deltorphins, based on nmr studies in DMSO and cryoprotective mixtures and internal energy calculations, showed that the enormous differences in receptor selectivity can be interpreted on the basis of receptor models for mu and delta opioids that recognize the same beta-turn in the N-terminal part, but discriminate for the conformation and polarity of the C-terminal part. Here we present the synthesis, biological activity, and conformational analysis in solution of three deltorphin analogues with very similar constitution, but with different net charge, different location of negative residues, or even without negative residues, which confirm these hypotheses and show that His4 can play a specific structural role.
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Affiliation(s)
- T Tancredi
- Istituto Chimica M.I.B. del CNR, Arco Felice, Italy
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34
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Petrilli P, Sepe C, Picone D, Caporale C, Caruso C. PROLANG: the SCAN command. Comput Appl Biosci 1990; 6:403. [PMID: 2257504 DOI: 10.1093/bioinformatics/6.4.403] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- P Petrilli
- Istituto di Industrie Agrarie, Università di Napoli, Italy
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35
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Picone D, D'Ursi A, Motta A, Tancredi T, Temussi PA. Conformational preferences of [Leu5]enkephalin in biomimetic media. Investigation by 1H NMR. Eur J Biochem 1990; 192:433-9. [PMID: 2209598 DOI: 10.1111/j.1432-1033.1990.tb19245.x] [Citation(s) in RCA: 66] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The conformation of [Leu5]enkephalin has been studied by 1H-NMR spectroscopy in media more like the actual environment in which the agonist-receptor interaction takes place than water, i.e. in three cryoprotective mixtures (dimethylformamide/water, methanol/water and ethylene glycol/water), in aqueous SDS and in two neat solvents, dimethylformamide and acetonitrile, whose dielectric constants (36.7 and 37.5) are intermediate between that of water and that of the lipid phase. In all cases examined, contrary to the studies in water or dimethylsulfoxide, we were able to detect numerous nuclear Overhauser effects, indicating that the media employed favour well-defined structures and/or reduce the internal motions of the peptide. Data from both organic solvents and cryoprotective mixtures suggest a 4----1 beta turn as the most probable structure of [Leu5]enkephalin in solution, whereas in SDS/H2O micelles the structural picture appears completely different, suggesting the presence of a 5----2 beta turn. The existence of two different preferred conformations of enkephalins may possibly be related to their ability to be effective towards both mu and delta opioid receptors.
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Affiliation(s)
- D Picone
- Dipartimento di Chimica, Università di Napoli Federico II, Italy
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36
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Balboni G, Marastoni M, Picone D, Salvadori S, Tancredi T, Temussi PA, Tomatis R. New features of the delta opioid receptor: conformational properties of deltorphin I analogues. Biochem Biophys Res Commun 1990; 169:617-22. [PMID: 2162669 DOI: 10.1016/0006-291x(90)90375-w] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Deltorphin I is an opioid peptide of sequence H-Tyr-D-Ala-Phe-Asp-Val-Val-Gly-NH2, recently isolated from the skin of Phyllomedusa bicolor. Its enormous selectivity towards the delta opioid receptor and the similarity of the conformation of the N-terminal part of the sequence with that of dermorphin (H-Tyr-D-Ala-he-Gly-Tyr-Pro-Ser-NH2), a mu selective peptide, prompted the synthesis, biological evaluation and comparative conformational study of four analogs. A 1H-NMR study showed that the conformational preferences of the N-terminal sequences of all peptides are similar. The different selectivities towards opioid receptors have been interpreted in terms of charge effects in the interaction with the membrane and at the receptor site and of hydrophobicity of the C-terminal part, when structured in a folded conformation.
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Affiliation(s)
- G Balboni
- Dipartimento di Scienze Farmaceutiche, University of Ferrara, Italy
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37
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Tamburrini M, Piccoli R, Picone D, Di Donato A, D'Alessio G. Dissociation and reconstitution of bovine seminal RNAase: construction of a hyperactive hybrid dimer. J Protein Chem 1989; 8:719-31. [PMID: 2624683 DOI: 10.1007/bf01024897] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The quaternary structure of bovine seminal ribonuclease, the only dimeric protein in the superfamily of ribonucleases, is maintained both by noncovalent forces and by two intersubunit disulfides. The available monomeric derivatives of the enzyme may not be reassembled into dimers. They are catalytically active, but do not retain certain properties of the dimeric enzyme, such as: (i) the ability to respond cooperatively to increasing substrate concentrations in the rate-limiting reaction step; and (ii) the antitumor and immunosuppressive actions. In this report we described the preparation of stable monomers of seminal ribonuclease which can be reassociated into covalent dimers indistinguishable from the native protein. With this procedure a hybrid dimer was constructed, made up of a native subunit associated to a subunit catalytically inactivated by selective alkylation of the active site His-119. This dimer was found to have enzymic properties typical of monomeric ribonucleases, such as a hyperbolic saturation curve in the hydrolytic rate-limiting step of the reaction. However, the hybrid dimer was one order-of-magnitude more active than the dimeric enzyme.
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Affiliation(s)
- M Tamburrini
- Department of Organic and Biological Chemistry, University of Naples
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38
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Temussi PA, Picone D, Tancredi T, Tomatis R, Salvadori S, Marastoni M, Balboni G. Conformational properties of deltorphin: new features of the delta-opioid receptor. FEBS Lett 1989; 247:283-8. [PMID: 2541018 DOI: 10.1016/0014-5793(89)81353-5] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Deltorphin is an opioid peptide with the sequence H-Tyr-D-Met-Phe-His-Leu-Met-Asp-NH2, recently isolated from the skin of Phyllomedusa sauvagei. Its enormous selectivity towards the delta-opioid receptor and the similarity of the N-terminal part of the sequence with that of dermorphin (H-Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH2), a mu selective peptide isolated from the same natural source, prompted a comparative conformational study. A 1H-NMR study in two different solvent systems showed that the conformational preferences of the N-terminal sequences of the two peptides are similar. The different selectivities towards opioid receptors have been interpreted in terms of charge effects. Besides a general trend consistent with the role of the membrane in the preselection of the peptides, the present study demonstrates the crucial role played by charged residues in the interaction inside the receptors.
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Affiliation(s)
- P A Temussi
- Dipartimento di Chimica, University of Naples, Napoli, Italy
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39
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Temussi PA, Picone D, Castiglione-Morelli MA, Motta A, Tancredi T. Bioactive conformation of linear peptides in solution: an elusive goal? Biopolymers 1989; 28:91-107. [PMID: 2541825 DOI: 10.1002/bip.360280112] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Bioactive peptides of natural origin have, in general, short linear sequences, and are characterized by a large conformational flexibility. It is very difficult to study their conformation in solution since they exist, almost invariably, as a complex mixture of numerous conformers, most of which are extended. The so-called bioactive conformation may be one of them, although the solvents used in solution studies often have properties drastically different from those of the biological system in which the peptide acts. There is, however, no simple way of identifying the bioactive conformation amid the many existing conformers. It is possible to approach a solution to this problem using two distinct strategies: (a) Limiting the conformational freedom of the peptide, e.g., by increasing the viscosity of the solution and decreasing the temperature, in the assumption that the bioactive conformation is, even slightly, more stable than the others. (b) Trying to mimic in solution the physicochemical features of the more reliable receptor models. These two approaches will be illustrated with examples taken mainly from opioid peptides.
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40
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Abstract
The synthetic peptide of sequence H-Ala-Ser-Thr-Thr-Thr-Asn-Tyr-Thr-OH, termed peptide T, a competitor of the Human Immunodeficiency Virus in the binding to human T cells, and its C-terminal pentapeptide fragment, were studied by 1H-nmr in DMSO solution to determine conformational preferences. The observation of nuclear Overhauser enhancements (NOEs) for both peptides, and unusual finding for small linear peptides, allowed complete sequence-specific resonance assignments. Long-range NOEs, ring-current shifts, and the very small temperature coefficient of the Thr8 NH chemical shift suggest, for the zwitterionic form of peptide T, the presence in solution of a beta-turn involving Thr5, Asn6, Tyr7 and Thr8. This conformational feature is consistent with previous structure-activity relationship studies indicating the invariance of the same residues in several potent pentapeptide analogues. The studied pentapeptide fragment, although less structured, shows some tendency to fold even in a polar solvent such as DMSO. Preliminary chemotaxis data on some pentapeptide analogues are consistent with our structural model.
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Abstract
Peptide T, an octapeptide of sequence ASTTTNYT that binds to human T cells, was studied as a zwitterion in DMSOd6 solution by means of proton NMR spectroscopy at 500 MHz. The unusual dispersion of the resonances of residues of the same type (T) makes it possible to assign all resonances to specific residues by means of several 2D techniques. The non-random nature of the conformation is substantiated by the observation of sequential nuclear Overhauser enhancements (NOEs). The low value of the temperature coefficient of the chemical shift of the NH of T8 and a diagnostic NOE between the NHs of T7 and T8 hint that a beta-turn including T5, N6, Y7 and T8 is a prominent conformational feature in solution. The ring current high field shifts of the methyl group and of the NH of T8 are consistent with an interaction with the side-chain of Y7, favoured by the beta-turn.
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Affiliation(s)
- D Picone
- Dipartimento di Chimica, Università di Napoli, Italy
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de Kretser TA, Thorne HJ, Picone D, Jose DG. Biochemical characterization of the monoclonal antibody-defined ovarian carcinoma-associated antigen SGA. Int J Cancer 1986; 37:705-12. [PMID: 3699932 DOI: 10.1002/ijc.2910370511] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The molecular nature of SGA, the ovarian-carcinoma-associated antigen defined by the MAb OM-1, has been determined. The cell-surface form of the SGA molecule is a glycoprotein with p1 less than 4.2, which on PAGE analysis has an apparent MW of approximately 360 kDa. This was the only OM-1-reactive species found on the cell surface. The apparent MW was unaffected by reducing conditions. The predominant cytoplasmic form of SGA is a non-glycosylated 170-kDa molecule with p1 6.5. Pulse-chase experiments were complicated by the extremely slow rate of SGA synthesis. However, the data indicate that the SGA molecule is synthesized as a 190-kDa protein, cleaved to yield a 170-kDa non-glycosylated intracellular form which is slowly glycosylated to the 360-kDa cell-surface species. Western blotting experiments revealed the presence of the 360-kDa glycosylated molecule in human ovarian cell culture supernatants.
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Caporale C, Fontanella A, Petrilli P, Pucci P, Molinaro MF, Picone D, Auricchio S. Isolation and characterization of dipeptidyl peptidase IV from human meconium. Functional role of beta-casomorphins. FEBS Lett 1985; 184:273-7. [PMID: 2860011 DOI: 10.1016/0014-5793(85)80621-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Dipeptidyl aminopeptidase IV (DAP-IV) (EC 3.4.14.1) was purified from meconium particles sedimenting at 105 000 X g. Its molecular properties and activity on synthetic and natural substrates (casomorphin and procasomorphin) were investigated.
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Abstract
Degradation of buffalo beta-casein by various physiological enzymes was studied. Digestion with gastric and pancreatic proteases plus leucine aminopeptidase did not release casomorphins but a putative precursor (procasomorphin) which was further digested by brush border peptidases into peptides differing from casomorphins.
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Abstract
In this work we describe that uncharged tRNAs or modified tRNAs lacking all or part of the C-C-A end (i.e., tRNA minus pCpCpA, tRNA minus pA, and tRNA minus A) can still influence the GTPase activity of the elongation factor Tu (EF-Tu), thus showing that, besides the aminoacylated 3'-end, other regions of the aa-tRNA interact with EF-Tu. The existence of an interaction between EF-Tu and truncated tRNAs was also confirmed by examining the dissociation of the EF-Tu-GTP complex: the rate of this reaction is decreased upon addition of tRNAVal1 minus pCpCpA. The effect on the EF-Tu GTPase activity of tRNAs deprived of the C-C-A 3'-end is still evident in the presence of C-C-A-aa. The stimulatory pattern obtained with C-C-A-Val at 5 mM MgCl2 is decreased upon addition of tRNAVal1 minus pCpCpA, tRNAVal1 minus pA, or tRNAVal1 minus A. This shows that the effect of the aminoacylated C-C-A 3'-end can be influenced via EF-Tu by the remaining regions of the tRNA, after cleavage of a bond in the 3'-extremity. However, also with an excess of tRNAVal1 minus pCpCpA over C-C-A-Val, no "aa-tRNA-like" effect, i.e., no inhibition of the EF-Tu GTPase, was obtained, suggesting that, upon binding with EF-Tu, a specific conformational change in the aa-tRNA molecule also takes place, regulating the expression of the GTPase activity. Our results unequivocally show that different regions of the aa-tRNA are needed for a coordinated interaction with EF-Tu.
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Parlato G, Pizzano R, Picone D, Guesnet J, Fasano O, Parmeggiani A. Different regions of aminoacyl-tRNA regulate the function of elongation factor Tu. J Biol Chem 1983; 258:995-1000. [PMID: 6130090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
In this work we show that intact aminoacyl-tRNA (aa-tRNA) and its 3' half-molecule, but not its 3' C-C-A-aa fragment, require selective ionic conditions for stimulating the mRNA-independent GTPase of elongation factor Tu (EF-Tu) in the presence of ribosomes.l Stimulation by aa-tRNA and its 3' half-molecule is only observed at 20 and 30 mM Mg2+ and not at 10 mM, where they exert inhibitory activity; by contrast, C-C-A-aa enhances the GTPase activity at all three of these Mg2+ concentrations. Ammonium ion is needed for stimulation by C-C-A-aa, whereas it inhibits the stimulation by aa-tRNA and its 3' half-molecule. The concentration of aminoacylated fragments needed for half-maximum stimulation follows this order: A-Val much greater than C-A-Val greater than C-C-A-Val much greater than 3' Val-tRNA1Val half-molecule greater than Val-tRNA1Val. The extent of maximum stimulation of the EF-Tu GTPase in the presence of ribosomes varies moderately depending on the aa-tRNA species; a clear dependence on the nature of the aminoacyl side chain is observed in the effects of their respective C-C-A-aa fragments tested (C-C-A-Arg, C-C-A-Val, C-C-A-Phe, C-C-A-Met, C-C-A-Lys). In the absence of ribosomes and at low [Mg2+], the one-round GTP hydrolysis by EF-Tu is enhanced by C-C-A-aa fragments, whereas it is inhibited by the corresponding aa-tRNAs. Our results suggest that besides the 3' aminoacylated extremity another region(s) of the aa-tRNA molecule controls the GTPase of EF-Tu. The "unspecific" stimulation by C-C-A-aa and the "specific," aa-tRNA-like effect of the 3' aa-tRNA half-molecule point to the importance of the T chi C loop and stem, as well as of the adjacent regions for the regulation of this function.
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Viola S, Sindoni G, Burrafato F, Ricotta M, Galanti P, Picone D, Di Francesco OM. [The Kottakis operation combined with drug therapy in the treatment of refractory ascites in liver cirrhosis. Personal observations]. MINERVA CHIR 1981; 36:1069-74. [PMID: 7290421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Mansueto S, Migneco G, Tripi S, Picone D, Miceli D. [Counterimmunoelectrophoresis on cellulose acetate membrane with a commercial lyophilized antigen in diagnosis of human hydatidosis]. Boll Ist Sieroter Milan 1979; 58:260-5. [PMID: 92994] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A very simplified method of crossed over electrophoresis (CIEP) was employed with a lyophilized commercially produced antigen (previously submitted to several freezing and thawing) and cellulose acetate membrane, for the diagnosis of human hydatidosis. Results are as follows: active hydatidosis (surgically confirmed): number of sera tested 35; positive 32 (91%). Sera of patients with parasitic and non parasitic illnesses (especially malignancies of liver and lung) did not show any precipitin lines. The pattern of immunoprecipitation is characteristically in the form of an "upper lip" or a thick and undulating "streak". The very thin arcs of precipitation which are occurring in some control sera, are to be considered negative. These results indicate that with regard to the rule of the "three S" (specificity, sensitivity and simplicity) the method appears sufficiently satisfactory.
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Mansueto S, Picone D, Di Rosa S, La Cascia C. [Counterimmunoelectrophoresis in the diagnosis of visceral leishmaniasis]. Boll Ist Sieroter Milan 1978; 57:622-30. [PMID: 90514] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Technique of counter current immunoelectrophoresis (C.I.E.P.) was employed for the diagnosis of V.L. using an antigen grossly extracted (by means of repeated freezing and thawing) from culture of Leishmania. 6 lots of antigen were prepared - in various time - at the same way. Positive results are obtained in V.L. from 83.3 to 94% (according to various lots of antigens). Few false positivity (from 1.4 to 8.8%) are obtained in sera from patients with other diseases (especially) cirrhosis and blood disorders. No positivity in controls (blood donors). The reproducibility of results appear satisfactory. Our results suggested that C.I.E.P., rapid and less sophisticated test, can be applied for the diagnosis of V.L. But false positivity and false negativity limit the value of these test.
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