1
|
|
2
|
Pankiewicz R, Schroeder G, Gierczyk B, Wojciechowski G, Brzezinski B, Bartl F, Zundel G. 7Li-NMR and FTIR studies of lithium, potassium, rubidium, and cesium complexes with ionophore lasalocid in solution. Biopolymers 2001; 62:173-82. [PMID: 11343288 DOI: 10.1002/bip.1012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [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: 11/11/2022]
Abstract
Lasalocid metal salts were combined with 1 : 1 lithium and 2:2 potassium, rubidium, and cesium to form complexes. The nature of the lasolocid salt complexes was studied in a solid and chloroform by FTIR spectroscopy in the middle and far IR regions. The process of the complexation of lithium was also studied by (7)Li-NMR. In chloroform a 1 : 1 complex of lasalocid and Li(+) ions was formed. Continuous absorption was observed in the far FTIR spectrum of this complex. It indicated large Li(+) polarizability, which was due to fast fluctuations of the Li(+) ions in the multiminima potentials, in the monomeric structure. In the lasalocid salt with the other monovalent cations (K(+), Rb(+), Cs(+)) 2:2 complexes were formed in which the cations showed cation polarizability, which strongly depended on the mass and the radius of the cations.
Collapse
Affiliation(s)
- R Pankiewicz
- Department of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznań, Poland
| | | | | | | | | | | | | |
Collapse
|
3
|
Jang GF, Kuksa V, Filipek S, Bartl F, Ritter E, Gelb MH, Hofmann KP, Palczewski K. Mechanism of rhodopsin activation as examined with ring-constrained retinal analogs and the crystal structure of the ground state protein. J Biol Chem 2001; 276:26148-53. [PMID: 11316815 PMCID: PMC1361691 DOI: 10.1074/jbc.m102212200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The guanine nucleotide-binding protein (G-protein)-coupled receptor superfamily (GPCR) is comprised of a large group of membrane proteins involved in a wide range of physiological signaling processes. The functional switch from a quiescent to an active conformation is at the heart of GPCR action. The GPCR rhodopsin has been studied extensively because of its key role in scotopic vision. The ground state chromophore, 11-cis-retinal, holds the transmembrane region of the protein in the inactive conformation. Light induces cis-trans isomerization and rhodopsin activation. Here we show that rhodopsin regenerated with a ring-constrained 11-cis-retinal analog undergoes photoisomerization; however, it remains marginally active because isomerization occurs without the chromophore-induced conformational change of the opsin moiety. Modeling the locked chromophore analogs in the active site of rhodopsin suggests that the beta-ionone ring rotates but is largely confined within the binding site of the natural 11-cis-retinal chromophore. This constraint is a result of the geometry of the stable 11-cis-locked configuration of the chromophore analogs. These results suggest that the native chromophore cis-trans isomerization is merely a mechanism for repositioning of the beta-ionone ring which ultimately leads to helix movements and determines receptor activation.
Collapse
Affiliation(s)
- G F Jang
- Department of Ophthalmology, University of Washington, Seattle, Washington 98195
| | | | | | | | | | | | | | | |
Collapse
|
4
|
Pankiewicz R, Wojciechowski G, Schroeder G, Brzezinski B, Bartl F, Zundel G. FT-IR study of the nature of K+, Rb+ and Cs+ cation motions in gramicidin A. J Mol Struct 2001. [DOI: 10.1016/s0022-2860(00)00840-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
5
|
Brzezinski B, Wojciechowski G, Bartl F, Zundel G. Formation of hydrogen-bonded chains through inter- and intra-molecular hydrogen bonds by a strong base of guanidine-like character and 2,2′-biphenols. J Mol Struct 2000. [DOI: 10.1016/s0022-2860(00)00664-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
6
|
Gierczyk B, Łęska B, Nowak-Wydra B, Schroeder G, Wojciechowski G, Bartl F, Brzezinski B. 15 N NMR and FTIR studies of 2,4-dinitroanilines and their salts. J Mol Struct 2000. [DOI: 10.1016/s0022-2860(00)00379-3] [Citation(s) in RCA: 4] [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: 10/16/2022]
|
7
|
Bartl F, Ritter E, Hofmann KP. FTIR spectroscopy of complexes formed between metarhodopsin II and C-terminal peptides from the G-protein alpha- and gamma-subunits. FEBS Lett 2000; 473:259-64. [PMID: 10812086 DOI: 10.1016/s0014-5793(00)01544-1] [Citation(s) in RCA: 29] [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: 11/18/2022]
Abstract
Metarhodopsin II (MII) provides the active conformation of rhodopsin for interaction with the G-protein, Gt. Fourier transform infrared spectra from samples prepared by centrifugation reflect the pH dependent equilibrium between MII and inactive metarhodopsin I. C-terminal synthetic peptides (Gtalpha(340-350) and Gtgamma(60-71)farnesyl) stabilize MII. We find that both peptides cause similar spectral changes not seen with control peptides (Gtalpha (K341R, L349A) and non-farnesylated Gtgamma). The spectra reflect all the protonation dependent bands normally observed when MII is formed at acidic pH. Beside the protonation dependent bands, additional features, similar with both peptides, appear in the amide I and II regions.
Collapse
Affiliation(s)
- F Bartl
- Institut für Medizinische Physik und Biophysik, Universitätsklinikum Charité, Humboldt Universität zu Berlin, Ziegelstrasse 5-9, D-10098, Berlin, Germany
| | | | | |
Collapse
|
8
|
Schroeder G, Gierczyk B, Brzezinski B, Różalski B, Bartl F, Zundel G, Sośnicki J, Grech E. 23 Na NMR and FT-IR studies of sodium complexes with the ionophore lasalocid in solution. J Mol Struct 2000. [DOI: 10.1016/s0022-2860(99)00139-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
9
|
Schroeder G, Łȩska B, Gierczyk B, Eitner K, Wojciechowski G, Różalski B, Bartl F, Brzezinski B. Studies of complexation of metal cations by tris(3,6-dioxaheptyl)amine in solution. J Mol Struct 1999. [DOI: 10.1016/s0022-2860(99)00011-3] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
10
|
Bartl F, Palm D, Schinzel R, Zundel G. Proton relay system in the active site of maltodextrinphosphorylase via hydrogen bonds with large proton polarizability: an FT-IR difference spectroscopy study. European Biophysics Journal 1999; 28:200-7. [PMID: 10232933 DOI: 10.1007/s002490050200] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Maltodextrinphosphorylase (MDP) was studied in the pH range 5.4-8.4 by Fourier transform infrared (FT-IR) spectroscopy. The pK(a) value of the cofactor pyridoxalphosphate (PLP) was found between 6.5 and 7.0, which closely resembles the second pK(a) of free PLP.FT-IR difference spectra of the binary complex of MDP + alpha-D-glucose-1-methylenephosphonate (Glc-1-MeP) minus native MDP were taken at pH 6.9. Following binary complex formation, two Lys residues, tentatively assigned to the active site residues Lys533 and Lys539, became deprotonated, and PLP as well as a carboxyl group, most likely of Glu637, protonated. A system of hydrogen bonds which shows large proton polarizability due to collective proton tunneling was observed connecting Lys533, PLP, and Glc-1-MeP. A comparison with model systems shows, furthermore, that this hydrogen bonded chain is highly sensitive to local electrical fields and specific interactions, respectively. In the binary complex the proton limiting structure with by far the highest probability is the one in which Glc-1-MeP is singly protonated. In a second hydrogen bonded chain the proton of Lys539 is shifted to Glu637. In the binary complex the proton remains located at Glu637. In the ternary complex composed of phosphorylase, glucose-1-phosphate (Glc-1-P), and the nonreducing end of a polysaccharide chain (primer), a second proton may be shifted to the phosphate group of Glc-1-P. In the doubly protonated phosphate group the loss of mesomeric stabilization of the phosphate ester makes the C1-O1 bond of Glc-1-P susceptible to bond cleavage. The arising glucosyl carbonium ion will be a substrate for nucleophilic attack by the nonreducing terminal glucose residue of the polysaccharide chain.
Collapse
Affiliation(s)
- F Bartl
- Humboldt University of Berlin, Institute of Medical Physics and Biophysics, Germany.
| | | | | | | |
Collapse
|
11
|
Abstract
We synthesized a triamide of Kemp's acid with two cysteine groups and one histidine group (compound 1), and a triamide of 1,3,5-pentane tricarboxylic acid with tyrosine, histidine, and arginine molecules (compound 2). From compound 1 we obtained the hydrated Zn2+ complex, compound 3. The FT-IR spectra of various complexes of compounds 1-3 with NAD+ show no IR continua and hence, no hydrogen-bonded chains with proton polarizability are present. In the case of the complex (compounds 2 and 3 and NAD+) an intense continuum demonstrates that a hydrogen-bonded chain is formed with large proton polarizability due to collective proton motion. This proton pathway is discussed. The O atom of the nicotinamide group of NAD+ is a strong hydrogen bond acceptor. This result is discussed with regard to the catalytic mechanism.
Collapse
Affiliation(s)
- B Brzezinski
- Faculty of Chemistry, Adam Mickiewicz University, Poznan, Poland
| | | | | | | |
Collapse
|
12
|
Bartl F, Deckers-Hebestreit G, Altendorf K, Zundel G. The F0 complex of the ATP synthase of Escherichia coli contains a proton pathway with large proton polarizability caused by collective proton fluctuation. Biophys J 1995; 68:104-10. [PMID: 7711231 PMCID: PMC1281666 DOI: 10.1016/s0006-3495(95)80164-5] [Citation(s) in RCA: 36] [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: 01/26/2023] Open
Abstract
The F0 complex of the Escherichia coli ATP synthase embedded into cardiolipin liposomes was studied by FT-IR spectroscopy. For comparison, respective studies were performed with dried F0 liposomes and with F0 liposomes treated with N,N'-dicyclohexyl-carbodiimide (DCCD), which binds to Asp-61 of subunit c. Furthermore, the effect of H2O-->D2O exchange on the infrared spectrum was investigated. With F0 liposomes an infrared continuum is observed beginning at about 3000 cm-1 and extending toward smaller wavenumbers. In the DCCD-treated sample, this continuum is no longer observed. It vanishes also with drying of the liposomes. After H2O-->D2O exchange, this infrared continuum begins at about 2350 cm-1 and is less intense. All of these results demonstrate that a proton pathway in native F0 is present, in which the protons are shifted in a hydrogen-bonded chain with large proton polarizability due to collective proton tunneling. With the D2O-hydrated system, deuteron polarizability due to collective deuteron motion is observed, but the polarizability due to collective deuteron motion is smaller. Such pathways are very efficient, because they conduct protons or deuterons within picoseconds. These pathways lose their polarizability if the F0 complex is blocked by DCCD or if the liposomes are dried. On the basis of our results on the proton polarizability of hydrogen bonds and hydrogen-bonded systems and on the basis of structural data from the literature, the nature of the proton pathway of the F0 complex of E. coli is discussed.
Collapse
Affiliation(s)
- F Bartl
- Institute of Physical Chemistry, University of Munich, Germany
| | | | | | | |
Collapse
|
13
|
Abstract
Pneumoconiosis has been reported in tungsten carbide manufacture; past studies have suggested that adverse cobalt exposures may occur from wet process tungsten carbide grinding. This study shows that wet process tungsten carbide grinding without local exhaust can cause adverse cobalt exposures. Controls are summarized.
Collapse
|
14
|
Streian C, Pop T, Bartl F. [Cardiovascular changes in acute ethylism. Clinical and experimental data]. Med Interna (Bucur) 1971; 23:879-86. [PMID: 5117264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
15
|
Stanicu L, Mihăilescu M, Bartl F, Guţă M. [Antimyocardial antibodies and the evolution of myocardial and coronary pathology]. Med Interna (Bucur) 1970; 22:713-8. [PMID: 5456193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
16
|
Turcanu V, Bartl F, Fiat F. [Clinical and biological aspects of hyperlipemia]. Med Interna (Bucur) 1970; 22:489-93. [PMID: 4246119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
17
|
Gavrilescu S, Bartl F, Pop T. [Clinical and biological significance of the phenomenon of platelet adhesiveness and aggregation]. Med Interna (Bucur) 1969; 21:1411-30. [PMID: 4985383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
|
18
|
Anghelescu L, Băcanu G, Turcanu V, Bartl F. [Evaluation of the therapeutic effectiveness of a saluretic of the polythiazide type (Renese)]. Med Interna (Bucur) 1969; 21:205-10. [PMID: 5780237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
19
|
Gavrilesco S, Deutsch G, Bartl F. [On various pharmacodynamic effects of potassium and magnesium salts of D-L aspartic acid (effect on cell respiration, renal circulation and blood platelet adhesiveness)]. Agressologie 1968; 9:591-6. [PMID: 5710176] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
20
|
Gavrilescu M, Bartl F, Matcănu L. [Research on experimental atherosclerosis in rats. Correlations between the biochemical-humoral changes and morphological and vascular changes]. Med Interna (Bucur) 1968; 20:719-28. [PMID: 4241845] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
|
21
|
Prodan P, Bartl F, Coreanu G, Dinu F, Gavrilescu M, Nubert G, Parota G, Pop T. [Morphofunctional study of the small intestine in chronic hepatitis]. Med Interna (Bucur) 1968; 20:97-102. [PMID: 5668959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
|
22
|
Gavrilescu S, Bartl F, Csernik I, Anghelescu L, Moga D. [On various aspects of blood coagulation in obesity. II. Studies on the aggregation ("clumping") of thrombocytes "in vitro" and on the thromboplastin formation]. Dtsch Z Verdau Stoffwechselkr 1967; 27:191-5. [PMID: 5595739] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
|
23
|
Gavrilescu S, Athanasesco I, Streiano C, Bartl F, Gabriel L. [Treatment of chronic ischemia of the lower limbs by endoarterial administration of Mg and K aspartate]. Angeiologie 1966; 18:15-22. [PMID: 5921115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
24
|
Gavrilescu S, Bartl F, Fiat F. [On some aspects of blood coagulation in obesity. Effect of reducing diet]. Dtsch Z Verdau Stoffwechselkr 1966; 26:31-7. [PMID: 5998369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|
25
|
Gavrilescu S, Bartl F, Fiat F. [Change in the index of thrombocyte adhesiveness in atherosclerosis and obesity. The effect of weight reducing treatments]. Med Interna (Bucur) 1966; 18:185-91. [PMID: 5934943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
|