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Synytsya A, Janstová D, Šmidová M, Synytsya A, Petrtýl J. Evaluation of IR and Raman spectroscopic markers of human collagens: Insides for indicating colorectal carcinogenesis. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2023; 296:122664. [PMID: 36996519 DOI: 10.1016/j.saa.2023.122664] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2022] [Revised: 02/26/2023] [Accepted: 03/21/2023] [Indexed: 06/19/2023]
Abstract
Vibrational spectroscopic methods are widely used in the molecular diagnostics of carcinogenesis. Collagen, a component of connective tissue, plays a special role as a biochemical marker of pathological changes in tissues. The vibrational bands of collagens are very promising to distinguish between normal colon tissue, benign and malignant colon polyps. Differences in these bands indicate changes in the amount, structure, conformation and the ratio between the individual structural forms (subtypes) of this protein. The screening of specific collagen markers of colorectal carcinogenesis was carried out based on the FTIR and Raman (λex 785 nm) spectra of colon tissue samples and purified human collagens. It was found that individual types of human collagens showed significant differences in their vibrational spectra, and specific spectral markers were found for them. These collagen bands were assigned to specific vibrations in the polypeptide backbone, amino acid side chains and carbohydrate moieties. The corresponding spectral regions for colon tissues and colon polyps were investigated for the contribution of collagen vibrations. Mentioned spectral differences in collagen spectroscopic markers could be of interest for early ex vivo diagnosis of colorectal carcinoma if combine vibrational spectroscopy and colonoscopy.
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Affiliation(s)
- Alla Synytsya
- Department of Analytical Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic.
| | - Daniela Janstová
- Department of Analytical Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Miroslava Šmidová
- Department of Analytical Chemistry, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Andriy Synytsya
- Department of Carbohydrates and Cereals, University of Chemistry and Technology Prague, Technická 5, 166 28 Prague 6, Czech Republic
| | - Jaromír Petrtýl
- 4th Internal Clinic-Gastroenterology and Hepatology, 1(st) Faculty of Medicine, Charles University in Prague and General University Hospital in Prague, U Nemocnice 2, 128 00 Prague 2, Czech Republic
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2
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Hostert JD, Loney CN, Pramounmat N, Yan K, Su Z, Renner JN. Self-Assembly and Rearrangement of a Polyproline II Helix Peptide on Gold. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:6115-6122. [PMID: 33974431 DOI: 10.1021/acs.langmuir.0c03583] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Polyproline peptide sequences have gained popularity as anchors for peptide-based self-assembled monolayers (SAMs) due to their attractive properties. In this work, peptides containing the polyproline II helix (PPII) conformation were designed and assembled on gold (Au). A quartz crystal microbalance with dissipation was used to characterize SAM formation kinetics and related properties. Peptides were designed with the sequence (GPPPPPG)2C. It was discovered that a biexponential adsorption and rearrangement model describes the binding kinetics of the PPII-containing peptide on Au. In this model, an initial reversible binding step is followed by an irreversible rearrangement step, given by parameter kt. This study found kt to be approximately 0.00064 s-1 for the PPII-containing peptides. Similarly, we found that the adsorption of the PPII-containing peptide on Au, given by ΔGads, was thermodynamically favorable (-7.8 kcal mol-1) and comparable to other common thiol terminated SAMs on Au. Furthermore, we characterized SAM properties via QCM-D, Fourier-transform infrared (FTIR) spectroscopy, and electrochemical techniques to reveal high molecular density SAMs consisting of PPII helices. In addition, these SAMs were found to have high antifouling properties. Overall, this study characterizes the fundamental assembly mechanisms, particularly, rearrangement of PPII-containing peptides for the first time, which will be useful in the designing of future peptide-based SAMs with high surface coverage and antifouling properties.
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Affiliation(s)
- Jacob D Hostert
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Charles N Loney
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Nuttanit Pramounmat
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Katherine Yan
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Zihang Su
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
| | - Julie N Renner
- Department of Chemical and Biomolecular Engineering, Case Western Reserve University, Cleveland, Ohio 44106, United States
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3
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Zhu L, Yan Y, Gu DC, Lu Y, Gan JH, Tao NP, Wang XC, Xu CH. Rapid Quality Discrimination and Amino Nitrogen Quantitative Evaluation of Soy Sauces by Tri-Step IR and E-nose. FOOD ANAL METHOD 2018. [DOI: 10.1007/s12161-018-1284-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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4
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Yamazaki H, Beniash E, Yamakoshi Y, Simmer JP, Margolis HC. Protein Phosphorylation and Mineral Binding Affect the Secondary Structure of the Leucine-Rich Amelogenin Peptide. Front Physiol 2017; 8:450. [PMID: 28706493 PMCID: PMC5489624 DOI: 10.3389/fphys.2017.00450] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2017] [Accepted: 06/14/2017] [Indexed: 12/31/2022] Open
Abstract
Previously, we have shown that serine-16 phosphorylation in native full-length porcine amelogenin (P173) and the Leucine-Rich Amelogenin Peptide (LRAP(+P)), an alternative amelogenin splice product, affects protein assembly and mineralization in vitro. Notably, P173 and LRAP(+P) stabilize amorphous calcium phosphate (ACP) and inhibit hydroxyapatite (HA) formation, while non-phosphorylated counterparts (rP172, LRAP(-P)) guide the growth of ordered bundles of HA crystals. Based on these findings, we hypothesize that the phosphorylation of full-length amelogenin and LRAP induces conformational changes that critically affect its capacity to interact with forming calcium phosphate mineral phases. To test this hypothesis, we have utilized Fourier transform infrared spectroscopy (FTIR) to determine the secondary structure of LRAP(-P) and LRAP(+P) in the absence/presence of calcium and selected mineral phases relevant to amelogenesis; i.e., hydroxyapatite (HA: an enamel crystal prototype) and (ACP: an enamel crystal precursor phase). Aqueous solutions of LRAP(-P) or LRAP(+P) were prepared with or without 7.5 mM of CaCl2 at pH 7.4. FTIR spectra of each solution were obtained using attenuated total reflectance, and amide-I peaks were analyzed to provide secondary structure information. Secondary structures of LRAP(+P) and LRAP(-P) were similarly assessed following incubation with suspensions of HA and pyrophosphate-stabilized ACP. Amide I spectra of LRAP(-P) and LRAP(+P) were found to be distinct from each other in all cases. Spectra analyses showed that LRAP(-P) is comprised mostly of random coil and β-sheet, while LRAP(+P) exhibits more β-sheet and α-helix with little random coil. With added Ca, the random coil content increased in LRAP(-P), while LRAP(+P) exhibited a decrease in α-helix components. Incubation of LRAP(-P) with HA or ACP resulted in comparable increases in β-sheet structure. Notably, however, LRAP(+P) secondary structure was more affected by ACP, primarily showing an increase in β-sheet structure, compared to that observed with added HA. These collective findings indicate that phosphorylation induces unique secondary structural changes that may enhance the functional capacity of native phosphorylated amelogenins like LRAP to stabilize an ACP precursor phase during early stages of enamel mineral formation.
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Affiliation(s)
- Hajime Yamazaki
- Center for Biomineralization, The Forsyth InstituteCambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental MedicineBoston, MA, United States
| | - Elia Beniash
- Department of Oral Biology, Center for Craniofacial Regeneration, McGowan Institute for Regenerative Medicine, University of PittsburghPittsburgh, PA, United States
| | - Yasuo Yamakoshi
- Department of Biochemistry and Molecular Biology, School of Dental Medicine, Tsurumi UniversityYokohama, Japan
| | - James P Simmer
- Department of Biologic and Materials Sciences, University of Michigan School of DentistryAnn Arbor, MI, United States
| | - Henry C Margolis
- Center for Biomineralization, The Forsyth InstituteCambridge, MA, United States.,Department of Developmental Biology, Harvard School of Dental MedicineBoston, MA, United States
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Tsiolaki PL, Louros NN, Zompra AA, Hamodrakas SJ, Iconomidou VA. Unraveling the aggregation propensity of human insulin C-peptide. Biopolymers 2017; 108. [PMID: 27257781 DOI: 10.1002/bip.22882] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2016] [Revised: 05/19/2016] [Accepted: 05/31/2016] [Indexed: 12/27/2022]
Abstract
Over the last 20 years, proinsulin C-peptide emerged as an important player in various biological events. Much time and effort has been spent in exploring all functional features of C-peptide and recording its implications in Diabetes mellitus. Only a few studies, though, have addressed C-peptide oligomerization and link this procedure with Diabetes. The aim of our work was to examine the aggregation propensity of C-peptide, utilizing Transmission Electron Microscopy, Congo Red staining, ATR-FTIR, and X-ray fiber diffraction at a 10 mg ml-1 concentration. Our experimental work clearly shows that C-peptide self-assembles into amyloid-like fibrils and therefore, the aggregation propensity of C-peptide is a characteristic novel feature that should be related to physiological and also pathological conditions. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 108: 1-8, 2017.
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Affiliation(s)
- Paraskevi L Tsiolaki
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, Athens, 15701, Greece
| | - Nikolaos N Louros
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, Athens, 15701, Greece
| | | | - Stavros J Hamodrakas
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, Athens, 15701, Greece
| | - Vassiliki A Iconomidou
- Department of Cell Biology and Biophysics, Faculty of Biology, University of Athens, Panepistimiopolis, Athens, 15701, Greece
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6
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Nisin gold nanoparticles assemble as potent antimicrobial agent against Enterococcus faecalis and Staphylococcus aureus clinical isolates. J Drug Deliv Sci Technol 2017. [DOI: 10.1016/j.jddst.2016.11.002] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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7
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Franz J, Lelle M, Peneva K, Bonn M, Weidner T. SAP(E) – A cell-penetrating polyproline helix at lipid interfaces. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2016; 1858:2028-2034. [DOI: 10.1016/j.bbamem.2016.05.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 05/09/2016] [Accepted: 05/24/2016] [Indexed: 12/19/2022]
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8
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Han Y, Noguchi H, Sakaguchi K, Uosaki K. Formation process and solvent-dependent structure of a polyproline self-assembled monolayer on a gold surface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:11951-11957. [PMID: 21902210 DOI: 10.1021/la2020995] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The formation process and structure of a self-assembled monolayer (SAM) of lipoic-acid-terminated polyproline on a gold surface in aqueous solution were investigated by several techniques. The amount of polyproline molecules on the gold surface was determined from the area of the reductive desorption peak, and orientation and thickness of the polyproline SAM were determined in situ by attenuated total reflection infrared (ATR-IR) spectroscopy and ellipsometry. The kinetics of the polyproline SAM formation process were discussed on the basis of these results. The in situ IR study confirmed that the conformation of the polyproline SAM was changed by changing the solvent from water to methanol and methanol to water, as is the case for polyproline dissolved in solution.
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Affiliation(s)
- Ying Han
- Division of Chemistry, Graduate School of Science, Hokkaido University, Sapporo 060-0810, Japan
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9
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Beniash E. Biominerals--hierarchical nanocomposites: the example of bone. WILEY INTERDISCIPLINARY REVIEWS-NANOMEDICINE AND NANOBIOTECHNOLOGY 2011; 3:47-69. [PMID: 20827739 DOI: 10.1002/wnan.105] [Citation(s) in RCA: 148] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Many organisms incorporate inorganic solids in their tissues to enhance their functional, primarily mechanical, properties. These mineralized tissues, also called biominerals, are unique organo-mineral nanocomposites, organized at several hierarchical levels, from nano- to macroscale. Unlike man-made composite materials, which often are simple physical blends of their components, the organic and inorganic phases in biominerals interface at the molecular level. Although these tissues are made of relatively weak components under ambient conditions, their hierarchical structural organization and intimate interactions between different elements lead to superior mechanical properties. Understanding basic principles of formation, structure, and functional properties of these tissues might lead to novel bioinspired strategies for material design and better treatments for diseases of the mineralized tissues. This review focuses on general principles of structural organization, formation, and functional properties of biominerals on the example the bone tissues.
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Affiliation(s)
- Elia Beniash
- Department of Oral Biology, University of Pittsburgh, Pittsburgh, PA, USA.
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10
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Ahmed Z, Myshakina NS, Asher SA. Dependence of the AmII'p proline Raman band on peptide conformation. J Phys Chem B 2009; 113:11252-9. [PMID: 19627094 PMCID: PMC2742972 DOI: 10.1021/jp809857y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
We utilized UV resonance Raman (UVRR) measurements and density functional theory (DFT) calculations to relate the AmII'p frequency to the psi angle. The AmII'p frequency shifts by approximately 25 cm(-1) as the psi angle is varied over allowed angles of the Pro peptide bond. The AmII'p frequency does not show any significant dependence on the phi dihedral angle. The conformation sensitivity of the AmII'p frequency derives from conformation-induced changes in the planarity of the Pro peptide bond; psi angle changes push the amide nitrogen out of the peptide bond plane. We use this AmII'p frequency dependence on the psi angle to track temperature-induced conformation changes in a polyproline peptide. The temperature-induced 7 cm(-1) downshift in the AmII'p frequency of the polyproline peptide results from an approximately 45 degrees rotation of the psi dihedral angle from psi = 145 degrees (ideal PPII conformation) to psi = 100 degrees (collapsed PPII conformation).
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Affiliation(s)
- Zeeshan Ahmed
- Department of Chemistry, University of Pittsburgh, PA 15260
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11
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NAGARAJ R, VENKATACHALAPATHI Y, BALARAM P. ROTATIONAL ISOMERISM ABOUT THE Cα-CO BOND IN PROLINE DERIVATIVES. ACTA ACUST UNITED AC 2009. [DOI: 10.1111/j.1399-3011.1980.tb02589.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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12
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Svintradze DV, Mrevlishvili GM, Metreveli N, Jariashvili K, Namicheishvili L, Skopinska J, Sionkowska A. Collagen-DNA complex. Biomacromolecules 2007; 9:21-8. [PMID: 18052128 DOI: 10.1021/bm7008813] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Previously presented models of collagen-DNA (7) and collagen-siRNA (8) complexes point to a general description of delivery systems and indicate to what specific topology that system should be equipped with to effectively deliver the gene into the living body via in vivo and in vitro injection. We focused our interest on the nature of collagen-DNA complex structure and the molecular and environmental determinants of the self-association processes of collagen with the presence of DNA. In this aspect, the self-association of collagen-DNA complex offers an opportunity to characterize a unique system, which may be related to the general mechanisms of self-association of fiber macromolecules by water bridges. For characterizing the collagen-DNA interaction, we used FTIR-ATR, NMR, and AFM experiments done on a separate collagen film, DNA film, and on the peptide-DNA aqueous solution. We demonstrate that collagen-DNA spontaneously forms self-assembling complex systems in aqueous solution. Such self-association of the complex could be induced by electrostatic interactions between neutral collagen cylinders, having strong dipole moment, and negatively charged DNA cylinders. A final complex could be formed by hydrogen bonds between specified donor groups of collagen and phosphate acceptor groups of DNA. According to FTIR measurements, a collagen triple helix should not change global conformation during collagen-DNA complex formation.
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Affiliation(s)
- David V Svintradze
- Faculty of Physics and Mathematics, Ilia Chavchavadze State University, Chavchavadze Av. 32,Tbilisi 0157, Georgia.
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Elangovan S, Margolis HC, Oppenheim FG, Beniash E. Conformational changes in salivary proline-rich protein 1 upon adsorption to calcium phosphate crystals. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2007; 23:11200-5. [PMID: 17880251 DOI: 10.1021/la7013978] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Conformational analyses of PRP1, a proline-rich acidic salivary protein and major component of the acquired enamel pellicle, have been carried out in solution and upon binding to two enamel prototypes, hydroxyapatite (HA) and carbonated hydroxyapatite (CHA), using Fourier transform infrared spectroscopy (FTIR) in attenuated total reflection (ATR) mode. We have shown for the first time that, in solution, large portions of PRP1 adopt the hydrated polyproline type II (PPII) helical structure in addition to the random coil structure, with the maximum absorbance of the amide I band around 1620 cm(-1). Upon binding to HA or CHA, the protein undergoes significant conformational changes, loosing a considerable portion of hydrated PPII and random coil domains with a shift in the maximum absorbance to 1666 cm(-1), indicating that a large fraction of the protein is composed of beta turns. A small fraction of PPII in a calcium-bound or anhydrous form (approximately 1642 cm(-1)) was also observed in the HA- and CHA-bound proteins, which could play a role in protein-mineral interactions. The conformational changes in PRP1 adsorbed on CHA and HA were similar in nature; however, these changes were greater in the protein bound to HA. Interestingly, these results are in agreement with protein adsorption data that show that less protein is adsorbed onto CHA than onto HA. Our results demonstrate that binding to apatitic mineral surfaces leads to major conformational changes in PRP1, which might reflect the expulsion of water and the formation of protein-mineral and/or protein-protein interactions in the adsorbed layer.
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Affiliation(s)
- Satheesh Elangovan
- Department of Periodontology and Oral Biology, Boston University Goldman School of Dental Medicine, Suite W201, 700 Albany Street, Boston, Massachusetts 02118-2392, USA
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Barth A. Infrared spectroscopy of proteins. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2007; 1767:1073-101. [PMID: 17692815 DOI: 10.1016/j.bbabio.2007.06.004] [Citation(s) in RCA: 2768] [Impact Index Per Article: 162.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2007] [Revised: 06/18/2007] [Accepted: 06/19/2007] [Indexed: 12/12/2022]
Abstract
This review discusses the application of infrared spectroscopy to the study of proteins. The focus is on the mid-infrared spectral region and the study of protein reactions by reaction-induced infrared difference spectroscopy.
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Affiliation(s)
- Andreas Barth
- Department of Biochemistry and Biophysics, The Arrhenius Laboratories for Natural Sciences, Stockholm University, S-106 91 Stockholm, Sweden.
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15
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Affiliation(s)
- Haizhen Zhong
- Department of Medicinal Chemistry, College of Pharmacy, The University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109-1065
| | - Heather A. Carlson
- Department of Medicinal Chemistry, College of Pharmacy, The University of Michigan, 428 Church Street, Ann Arbor, Michigan 48109-1065
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16
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Barth A. The infrared absorption of amino acid side chains. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2001; 74:141-73. [PMID: 11226511 DOI: 10.1016/s0079-6107(00)00021-3] [Citation(s) in RCA: 877] [Impact Index Per Article: 38.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Amino acid side chains play fundamental roles in stabilising protein structures and in catalysing enzymatic reactions. These fields are increasingly investigated by infrared spectroscopy at the molecular level. To help the interpretation of the spectra, a review of the infrared absorption of amino acid side chains in H(2)O and 2H(2)O is given. The spectral region of 2600-900cm(-1) is covered.
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Affiliation(s)
- A Barth
- Institut für Biophysik, Johann Wolfgang Goethe-Universität, Theodor Stern-Kai 7, Haus 74, D-60590 Frankfurt am Main, Germany.
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17
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Dukor RK, Keiderling TA. Mutarotation studies of poly-L-proline using FTIR, electronic and vibrational circular dichroism. ACTA ACUST UNITED AC 1998. [DOI: 10.1002/(sici)1520-6343(1996)2:2<83::aid-bspy2>3.0.co;2-t] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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18
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Dukor RK, Keiderling TA. Reassessment of the random coil conformation: vibrational CD study of proline oligopeptides and related polypeptides. Biopolymers 1991; 31:1747-61. [PMID: 1793813 DOI: 10.1002/bip.360311409] [Citation(s) in RCA: 206] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The "random coil" conformational problem is examined by comparison of vibrational CD (VCD) spectra of various polypeptide model systems with that of proline oligomers [(Pro)n] and poly(L-proline). VCD, ir and uv CD spectra of blocked L-proline oligopeptides [(Pro)n, n = 2-12] in different solvents are reported and compared to the spectra of poly(L-proline) II, poly(L-glutamic acid), and unblocked proline oligomers. Based on the chain-length dependence of the VCD and electronic CD (ECD) spectra of proline oligomers, it is established that VCD spectra are dominated by short-range interactions. The VCD of random coil model polypeptides is shown to be identical in shape but smaller in magnitude than poly(L-proline) II and of similar magnitude to that of (Pro)n (n = 3, 4). Based on the spectral evidence, it is concluded that the "random coil" conformation has a large fraction of helical regions, conformationally similar to the left-handed, 3(1) polyproline II helix, as was previously suggested by Krimm and co-workers. This conclusion is further supported by studies of effects of salt (CaCl2, LiBr, LiClO4), temperature (5-75 degrees C), and pH on the VCD spectra of L-proline oligomers, poly(L-proline) II, and poly(L-glutamic acid). These show that, after each of these perturbations, a significant local ordering remains in the oligomers and polymers studied, and that charged polypeptides such as poly(L-glutamic acid) are more flexible than are polyproline or even L-proline oligomers.
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Affiliation(s)
- R K Dukor
- Department of Chemistry, University of Illinois, Chicago 60680
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19
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Dukor RK, Keiderling TA, Gut V. Vibrational circular dichroism spectra of unblocked proline oligomers. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1991; 38:198-203. [PMID: 1761366 DOI: 10.1111/j.1399-3011.1991.tb01429.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Vibrational Circular Dichroism (VCD) spectra of unblocked L-proline oligopeptides, (Pro)n n = 3 to 7, dissolved in D2O are reported. For these oligomers, the VCD spectra can be attributed to a conformational dominance of the trans amide conformation with subunits interrelated by a left-handed twist, particularly for the longer oligomers. As a function of oligomer length, formation of this conformation starts at n = 3; and by n = 5 a spectrum closely resembling that of the poly-L-proline II helix in shape and magnitude is seen. The VCD data are compared with previous (Pro)n results using IR, CD, Raman and NMR spectroscopies, and reasons for the variations in interpretation are discussed.
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Affiliation(s)
- R K Dukor
- Department of Chemistry, University of Illinois, Chicago
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20
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Spin-label study of the conformational states of polypeptide models of histones. Chem Nat Compd 1986. [DOI: 10.1007/bf00574740] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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21
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Pulla Rao C, Balaram P, Rao C. 13C-n.m.r. studies of the conformational changes in proline oligomers brought about by lithium and calcium salts. Int J Biol Macromol 1983. [DOI: 10.1016/0141-8130(83)90044-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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22
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Nemetschek T, Jelinek K, Knörzer E, Mosler E, Nemetschek-Gansler H, Riedl H, Schilling V. Transformation of the structure of collagen. A time-resolved analysis of mechanochemical processes using synchrotron radiation. J Mol Biol 1983; 167:461-79. [PMID: 6864805 DOI: 10.1016/s0022-2836(83)80345-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Mechanochemically induced molecular transformations of collagen fibres were analysed using time-resolved small-angle diffraction spectra and histomechanical measurements. In particular, the influence of aqueous and methanolic perchlorate solutions was examined. According to a transformation continuing from the periphery towards the centre, the macroscopic contraction that is completed less than five minutes after incubation with perchlorate is caused by peripherally transformed fibrils only, whereas the centrally situated fibrils first undergo an accordion-like folding, but after more than 20 minutes are transformed similarly. The triple-helical transformation is preceded by a structure-breaking effect on structural water that can be monitored in time-resolved diffraction spectra. The combined loss of meridional low-angle reflections and cross-striated fibrils in micrographs is irreversible. By dialysis of colloidally dissolved collagen against a solution of ATP, however, segment-long spacing aggregates are obtained. Under isometric conditions, an instantaneous transformation of intermittent regions leads to an increase in the long period of adjacent, still structured regions of the same fibril that is correlated with a delayed increase in tension in the fibre. Increase of tension under isometric conditions as well as the flow-properties of a fibre relaxed in perchlorate are interpreted in terms of the parallel sliding of subunits of varying lengths, which has been demonstrated by diffraction analysis.
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Han SL, Stimson ER, Maxfield FR, Scheraga HA. Spectroscopic study of the conformations of proline-containing oligopeptides in the crystalline state and in solution. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1981; 17:297-315. [PMID: 7287301 DOI: 10.1111/j.1399-3011.1981.tb01996.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
A conformational study has been carried out on a series of linear proline-containing oligopeptides (ZGP, ZGPL, ZGPLG and ZGPLGP) in both the crystalline state and in DMSO-d6 solution, using Raman and n.m.r. spectroscopy. The amide I and III bands in the Raman spectra of the crystalline forms indicate the presence of the type I beta-bend conformation in ZGPLG and ZGPLGP, but not in ZGP and ZGPL. This result is in agreement with X-ray data on these molecules. The Raman spectra of these peptides in solution indicate that more than one conformation is present, i.e. that the beta-bend structure of the solid form of ZGPLG and ZGPLGP is destabilized by DMSO-d6. 13C and 1H n.m.r. data also demonstrate the presence of more than one conformation in ZGP, ZGPL, ZGPLG and ZGPLGP in DMSO-d6 solution. These isomers differ in their conformation (cis and trans) about their Gly-Pro peptide bonds and possibly about the c alpha-C' bond of the C-terminal proline in ZGPLGP. For ZGP, ZGPL, ZGPLG and ZGPLGP, the ensemble of conformations in DMSO-d6 includes C5 and C7 hydrogen-bonded rings; in addition, ZGPLGP may contain a small percentage of a beta-bend conformation (at Pro2-Leu3) with trans peptides in both Gly-Pro moieties.
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Boni R, Di Blasi R, Farina A, Verdini AS. Conformational properties of the sequential polyproline analogs poly(Pro-Aze-Pro) and poly(Aze-Pro-Aze). Biopolymers 1976; 15:1233-41. [PMID: 949532 DOI: 10.1002/bip.1976.360150702] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Lo JT, Mattice WL. Evidence from circular dichroism for the binding of hydrogen ions and calcium ions by poly (L-proline). Biopolymers 1976; 15:15-9. [PMID: 1244897 DOI: 10.1002/bip.1976.360150103] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Rabolt JF, Wedding W, Johnson KW. A vitrational study of poly (L-proline) I and II in the far infrared. Biopolymers 1975; 14:1615-22. [PMID: 1156658 DOI: 10.1002/bip.1975.360140806] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Doyle BB, Bendit EG, Blout ER. Infrared spectroscopy of collagen and collagen-like polypeptides. Biopolymers 1975; 14:937-57. [PMID: 1156652 DOI: 10.1002/bip.1975.360140505] [Citation(s) in RCA: 375] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
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Balasubramanian D. Critique of the interpretation of the circular dichroism of unordered polypeptides and proteins. Biopolymers 1974; 13:407-10. [PMID: 4820069 DOI: 10.1002/bip.1974.360130216] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Investigation of the conformational transition in crystalline N-acetyl-L-proline methylamide by ir spectroscopy in the central and far regions. J STRUCT CHEM+ 1974. [DOI: 10.1007/bf00753802] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Mattice WL. The effect of temperature and salt concentration on the circular dichroism exhibited by unionized derivatives of L-alanine in aqueous solution. Biopolymers 1974; 13:169-83. [PMID: 4818125 DOI: 10.1002/bip.1974.360130111] [Citation(s) in RCA: 45] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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Schleich T, Yeh Y. The solution behavior of poly-L-proline: I. Light scattering studies in water and concentrated aqueous neutral salt solutions. Biopolymers 1973. [DOI: 10.1002/bip.1973.360120505] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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