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Ohkuri T, Nagatomo S, Oda K, So T, Imoto T, Ueda T. A Protein’s Conformational Stability Is an Immunologically Dominant Factor: Evidence That Free-Energy Barriers for Protein Unfolding Limit the Immunogenicity of Foreign Proteins. THE JOURNAL OF IMMUNOLOGY 2010; 185:4199-205. [DOI: 10.4049/jimmunol.0902249] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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2
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Gilbert HF. Molecular and cellular aspects of thiol-disulfide exchange. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 63:69-172. [PMID: 2407068 DOI: 10.1002/9780470123096.ch2] [Citation(s) in RCA: 251] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- H F Gilbert
- Verna and Marrs McLean Department of Biochemistry, Baylor College of Medicine, Houston, Texas 77030
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3
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Abstract
I have pursued research on lysozymes for 42 years. During that time, I made Several new findings, some of them by chance. My enjoyment of the following areas is reviewed: the story of tryptophan; protease digestion mechanisms; peptide mapping with RP-HPLC; gene engineering; renaturation of protein; catalytic residues; fluctuation and function; stabilization; folding; antigenecity; tolerance; and various lysozymes.
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Affiliation(s)
- Taiji Imoto
- Graduate School of Pharmaceutical Sciences, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka 812-8582, Japan
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4
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Zavodszky M, Chen CW, Huang JK, Zolkiewski M, Wen L, Krishnamoorthi R. Disulfide bond effects on protein stability: designed variants of Cucurbita maxima trypsin inhibitor-V. Protein Sci 2001; 10:149-60. [PMID: 11266603 PMCID: PMC2249841 DOI: 10.1110/ps.26801] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Attempts to increase protein stability by insertion of novel disulfide bonds have not always been successful. According to the two current models, cross-links enhance stability mainly through denatured state effects. We have investigated the effects of removal and addition of disulfide cross-links, protein flexibility in the vicinity of a cross-link, and disulfide loop size on the stability of Cucurbita maxima trypsin inhibitor-V (CMTI-V; 7 kD) by differential scanning calorimetry. CMTI-V offers the advantage of a large, flexible, and solvent-exposed loop not involved in extensive intra-molecular interactions. We have uncovered a negative correlation between retention time in hydrophobic column chromatography, a measure of protein hydrophobicity, and melting temperature (T(m)), an indicator of native state stabilization, for CMTI-V and its variants. In conjunction with the complete set of thermodynamic parameters of denaturation, this has led to the following deductions: (1) In the less stable, disulfide-removed C3S/C48S (Delta Delta G(d)(50 degrees C) = -4 kcal/mole; Delta T(m) = -22 degrees C), the native state is destabilized more than the denatured state; this also applies to the less-stable CMTI-V* (Delta Delta G(d)(50 degrees C) = -3 kcal/mole; Delta T(m) = -11 degrees C), in which the disulfide-containing loop is opened by specific hydrolysis of the Lys(44)-Asp(45) peptide bond; (2) In the less stable, disulfide-inserted E38C/W54C (Delta Delta G(d)(50 degrees C) = -1 kcal/mole; Delta T(m) = +2 degrees C), the denatured state is more stabilized than the native state; and (3) In the more stable, disulfide-engineered V42C/R52C (Delta Delta G(d)(50 degrees C) = +1 kcal/mole; Delta T(m) = +17 degrees C), the native state is more stabilized than the denatured state. These results show that a cross-link stabilizes both native and denatured states, and differential stabilization of the two states causes either loss or gain in protein stability. Removal of hydrogen bonds in the same flexible region of CMTI-V resulted in less destabilization despite larger changes in the enthalpy and entropy of denaturation. The effect of a cross-link on the denatured state of CMTI-V was estimated directly by means of a four-state thermodynamic cycle consisting of native and denatured states of CMTI-V and CMTI-V*. Overall, the results show that an enthalpy-entropy compensation accompanies disulfide bond effects and protein stabilization is profoundly modulated by altered hydrophobicity of both native and denatured states, altered flexibility near the cross-link, and residual structure in the denatured state.
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Affiliation(s)
- M Zavodszky
- Department of Biochemistry, Kansas State University, Manhattan, Kansas 66506, USA
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5
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Ueda T, Masumoto K, Ishibashi R, So T, Imoto T. Remarkable thermal stability of doubly intramolecularly cross-linked hen lysozyme. PROTEIN ENGINEERING 2000; 13:193-6. [PMID: 10775660 DOI: 10.1093/protein/13.3.193] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
In order to examine how a protein can be effectively stabilized, two intramolecular cross-links, Glu35-Trp108 and Lys1-His15, which have few unfavorable interactions in the folded state, were simultaneously introduced into hen lysozyme. Both of the intramolecularly cross-linked lysozymes, 35-108 CL and 1-15 CL, containing cross-links Glu35-Trp108 and Lys1-His15, respectively, showed increases in thermal stability of 13.9 and 5.2 degrees C, respectively, over that of wild type, at pH 2.7. On the other hand, a doubly cross-linked lysozyme showed an increase in thermal stability of 20.8 degrees C over that of wild type, under identical conditions. Since the sum of the differences in denaturation temperature between wild type and each of the cross-linked lysozymes was nearly equal to that between wild type and the doubly cross-linked lysozyme, we suggest that the efficient stabilization of the lysozyme molecule was the direct result of the double intramolecular cross-links.
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Affiliation(s)
- T Ueda
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-8582, Japan
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6
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So T, Ito HO, Koga T, Watanabe S, Ueda T, Imoto T. Depression of T-cell epitope generation by stabilizing hen lysozyme. J Biol Chem 1997; 272:32136-40. [PMID: 9405412 DOI: 10.1074/jbc.272.51.32136] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Conformational stability of proteins is an important factor that determines their resistance/susceptibility to proteolytic digestion. Intracellular proteolysis is the key step in antigen presentation events for protein antigens; hence, it is likely that increasing protein stability reduces the antigenicity of proteins. We prepared three hen egg white lysozyme derivatives possessing different stabilities by chemical modification to clarify the relationship between conformational stability and the antigenicity of the protein. One of the derivatives was conformationally unstabilized by removing one intramolecular disulfide bond, whereas the two others were stabilized by the addition of an intramolecular cross-link. The antigenicity of these derivatives was evaluated using hen egg white lysozyme-specific T-cell hybridoma cells and a B-lymphoma cell line, A20, as antigen-presenting cells. With an increase in conformational stability, the T-cell response decreased. However, the reduction was not derived from the inefficiency of internalization to A20 cells nor the alteration of antigenicity by chemical modifications. Moreover, from analyses of their susceptibility to proteolysis and the kinetics of presentation of the T-cell epitope, it was confirmed that increasing protein stability led to the depression of T-cell epitope generation by increasing resistance to proteolysis. These results have an important implication in devising a new strategy for manipulating T-cell response by the stability of protein antigen.
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Affiliation(s)
- T So
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka 812-82, Japan
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7
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Löster K, Josić D. Analysis of protein aggregates by combination of cross-linking reactions and chromatographic separations. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 699:439-61. [PMID: 9392387 DOI: 10.1016/s0378-4347(97)00215-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Chemical cross-linking provides a method that covalently bridges near-neighbour associations within proteins and protein aggregates. Combined with chromatographic separations and protein-chemical methods, it may be used to localize and to investigate three-dimensional relations as present under natural conditions. This paper reviews the chemistry and application of cross-linking reagents and the development of combination experimental approaches in view of chromatographic separations and cross-linking reactions. Investigations of homooligomeric and heterooligomeric protein associations as well as conformational analysis are presented.
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Affiliation(s)
- K Löster
- Institut für Molekularbiologie und Biochemie, Freie Universität Berlin, Berlin-Dahlem, Germany
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8
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Abstract
As the most extensively investigated model protein, the protein engineering of lysozyme is described. By utilizing modifications made possible by chemical or gene engineering methods, we can get a better understanding of protein behaviour and we can also improve their properties. The results of the protein engineering of lysozyme are described, which give some ideas for a better understanding of the physiological function of proteins, their stabilization, and how to engineer a novel protein.
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Affiliation(s)
- T Imoto
- Graduate School of Pharmaceutical Sciences, Kyushu University, Fukuoka, Japan
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9
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Tatsumi E, Takahashi N, Hirose M. Denatured state of ovalbumin in high concentrations of urea as evaluated by disulfide rearrangement analysis. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(18)46895-0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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10
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Zhang T, Bertelsen E, Alber T. Entropic effects of disulphide bonds on protein stability. NATURE STRUCTURAL BIOLOGY 1994; 1:434-8. [PMID: 7664061 DOI: 10.1038/nsb0794-434] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
To measure the thermodynamic consequences of the reduction in the number of polypeptide-chain conformations that accompanies protein folding, we developed a method called loop permutation analysis. In this approach, the stabilizing contributions of three engineered disulphide bonds were compared in extended and circularly permutated mutants of phage T4 lysozyme. The observed differences in disulphide contributions, although qualitatively consistent with theoretical estimates, were not solely proportional to the differences in loop length. These findings suggest that in addition to the length of the chain, the polypeptide sequence may influence the energetic consequences of conformational restrictions.
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Affiliation(s)
- T Zhang
- Department of Molecular and Cell Biology, University of California, Berkeley 94720, USA
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11
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Disulfide mutants of the binding domain of the rat low affinity nerve growth factor receptor (p75NGFR). J Biol Chem 1994. [DOI: 10.1016/s0021-9258(19)78145-9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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12
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Zhou NE, Kay CM, Hodges RS. Disulfide bond contribution to protein stability: positional effects of substitution in the hydrophobic core of the two-stranded alpha-helical coiled-coil. Biochemistry 1993; 32:3178-87. [PMID: 8457578 DOI: 10.1021/bi00063a033] [Citation(s) in RCA: 136] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
To investigate the positional effect of the disulfide bond on the structure and stability of a two-stranded alpha-helical coiled-coil, an interchain disulfide bond was systematically introduced into the hydrophobic core of a de novo designed model coiled-coil at the N-terminus (position 2), C-terminus (position 33), and nonterminal positions a (positions 9, 16, 23, and 30) and d (positions 5, 12, 19, and 26). The rate of formation of a disulfide bond is faster at position d compared to at the corresponding position a under nondenaturing conditions, suggesting that position d is more suitable for engineering a disulfide bond. The structure and stability of the reduced and oxidized coiled-coils were determined by circular dichroism studies in the absence and presence of guanidine hydrochloride. Our results demonstrate that the improvement of protein stability by introduction of a disulfide bond is very relevant to its location and the most effective disulfide bonds are those that can be introduced in the hydrophobic core without any disruption of the protein structure. The disulfide bond at position d with near-optimal geometry does not perturb the coiled-coil structure and makes the largest contribution to coiled-coil stability. In contrast, the inappropriate geometry of the disulfide bond at nonterminal position a introduces a high strain energy on the disulfide bond which disrupts the coiled-coil structure. At positions a, the closer the disulfide bridge is to the center of the coiled-coil, the larger the disruption on the coiled-coil structure and the smaller the contribution the disulfide bond makes to coiled-coil stability. The computer modeling results also suggest that an insertion of an interchain disulfide bond at position a in the GCN4 leucine zipper X-ray structure has a higher potential energy than insertion at position d. The energy-minimized coiled-coil structure with an interchain disulfide bond at position a has a larger root mean square difference from the X-ray structure of GCN4 than the coiled-coil with a disulfide bond at position d. Because interhelical interactions are common in globular proteins as well as coiled-coils, the results obtained in this study will have general utility for selecting the sites for engineering disulfide bonds between alpha-helices.
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Affiliation(s)
- N E Zhou
- Department of Biochemistry, University of Alberta, Edmonton, Canada
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13
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Tidor B, Karplus M. The contribution of cross-links to protein stability: a normal mode analysis of the configurational entropy of the native state. Proteins 1993; 15:71-9. [PMID: 7680808 DOI: 10.1002/prot.340150109] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The vibrational entropy of native BPTI, with three disulfide bonds, was determined by use of normal mode calculations and compared with that of folded variants having either one less disulfide bond or lacking a peptide bond at the trypsin-reactive site. Favorable contributions to the free energy of 2.5-5.1 kcal/mol at 300 K were calculated for the reduction of disulfide bonds in the folded state, whereas no favorable contribution was found for the hydrolysis of the peptide bond cleaved by trypsin. This is on the order of the effect of disulfides in the unfolded state. The implications of these results for the stabilization of a folded protein by the introduction of cross-links are discussed.
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Affiliation(s)
- B Tidor
- Department of Chemistry, Harvard University, Cambridge, Massachusetts 02138
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14
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Kuroki R, Inaka K, Taniyama Y, Kidokoro S, Matsushima M, Kikuchi M, Yutani K. Enthalpic destabilization of a mutant human lysozyme lacking a disulfide bridge between cysteine-77 and cysteine-95. Biochemistry 1992; 31:8323-8. [PMID: 1525170 DOI: 10.1021/bi00150a028] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To understand the role of disulfide bridges in protein stability, the thermodynamic changes in the denaturation of two mutant human lysozymes lacking a disulfide bridge between Cys-77 and Cys-95 (C77A and C77/95A) were analyzed using differential scanning calorimetry (DSC). At pH 3.0 and 57 degrees C, the stabilities of both the C77A and C77/95A mutants were decreased about 4.6 kcal.mol-1 in Gibbs free energy change. Under the same conditions, the enthalpy changes (delta H) were 94.8 and 90.8 kcal.mol-1, respectively, which were smaller than that of the wild type (100.8 kcal.mol-1). The destabilization of the mutants was caused by enthalpic factors. Although X-ray crystallography indicated that the mutants preserve the wild-type tertiary structure, removal of the disulfide bridge increased the flexibility of the native state of the mutants. This was indicated both by an increase in the crystallographic thermal factors (B-factors) and by a decrease in the affinity of N-acetylglucosamine trimer [(NAG)3] observed using isothermal titration calorimetry (DTC) due to entropic effects. Thus, the effect of cross-linking on the stability of a protein is not solely explained by the entropy change in denaturation.
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Affiliation(s)
- R Kuroki
- Protein Engineering Research Institute, Osaka, Japan
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15
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Fujita Y, Noda Y. Effect of alkylation with different sized substituents on thermal stability of lysozyme. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1992; 40:103-9. [PMID: 1446966 DOI: 10.1111/j.1399-3011.1992.tb01456.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The amino groups of hen egg white lysozyme were reductively alkylated by the reaction with aliphatic aldehydes of various chain lengths and with two aldehydes of different steric hindrance at pH 7.5 and 4 degrees for 3 h. About four of the original six lysine residues were modified by the reaction with acetaldehyde, n-butylaldehyde or n-hexylaldehyde. About three lysine residues were 2,2-dimethylpropylated with trimethylacetaldehyde while a single residue was modified with benzaldehyde. The thermal stabilities of these alkylated lysozymes were investigated by differential scanning calorimetry (DSC) at different acidic pH values. Alkylation thermally destabilized the proteins, depending not only on the extent of modification but also on the size of the substituent. The alkylated derivatives were 8-19 kJ/mol less stable than native lysozyme at 25 degrees and pH 3.0. The temperature dependences of the activities of the alkylated lysozymes against ethylene glycol chitin indicated that the orders of the optimum temperatures and the maximum activities were exactly the same as the order of the thermal stabilities.
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Affiliation(s)
- Y Fujita
- Department of Chemistry, Hyogo College of Medicine, Japan
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16
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Kleanthous C, Reilly M, Cooper A, Kelly S, Price N, Coggins J. Stabilization of the shikimate pathway enzyme dehydroquinase by covalently bound ligand. J Biol Chem 1991. [DOI: 10.1016/s0021-9258(18)99103-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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17
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Denton ME, Scheraga HA. Spectroscopic, immunochemical, and thermodynamic properties of carboxymethyl(Cys6, Cys127)-hen egg white lysozyme. JOURNAL OF PROTEIN CHEMISTRY 1991; 10:213-32. [PMID: 1930635 DOI: 10.1007/bf01024786] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
A three-disulfide form of hen egg white lysozyme with Cys6 and Cys127 blocked by carboxymethyl groups was prepared, purified, and characterized for eventual use in protein folding experiments. Trypsin digestion followed by proline-specific endopeptidase digestion facilitated the unambiguous assignment of the disulfide bond pairings and the modified residues in this derivative. 3SS-lysozyme demonstrated nearly full enzymatic activity at its pH optimum, pH 5.5. The 3SS-lysozyme derivative and unmodified lysozyme were shown to be identical by CD spectroscopy at pH 3.6. Immunochemical binding assays demonstrated that the conformation of lysozyme was perturbed predominantly only locally by breaking and blocking the disulfide bond between Cys6 and Cys127. Both 3SS-lysozyme and unmodified lysozyme exhibited reversible thermally induced transitions at pH 2.0, but the Tm of 3SS-lysozyme, 18.9 degrees C, was found to be 34 degrees lower than that of native lysozyme under the same conditions. The conformational chemical potential of the denatured form of unmodified lysozyme was determined from the transition curves to be approximately 6.7 kcal/mol higher than that of the denatured form of 3SS-lysozyme, at pH 2.0 and 35 degrees C, if the conformational chemical potential for the folded forms of both 3SS-lysozyme and unmodified lysozyme is arbitrarily assumed to be 0.0 kcal/mol. A calculation of the increase in the theoretical loop entropy of denatured 3SS-lysozyme resulting from the cleavage of the Cys6-Cys127 disulfide bond, however, yielded a value of only 5.4 kcal/mol for the difference in conformational chemical potential. This suggests that, in addition to the entropic component, there is also an enthalpic contribution to the difference in the conformational chemical potential corresponding to approximately 1.3 kcal/mol. Thus, it is concluded that the reduction and blocking of the disulfide bond between Cys6 and Cys127 destabilizes 3SS-lysozyme relative to unmodified lysozyme predominantly by stabilizing the denatured conformation by increasing its chain entropy.
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Affiliation(s)
- M E Denton
- Baker Laboratory of Chemistry, Cornell University, Ithaca, New York 14853-1301
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18
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Abstract
The maintenance or stabilization of protein or enzyme function is of vital importance in Biotechnology. Investigations of thermophilic organisms, studies of denaturation and the use of enzymes in organic solvents have each contributed to an understanding of protein stability. Enzymes can reliably and reproducibly be stabilized by variety of means including immobilization, use of additives, chemical modification in solution and protein engineering. Examples of each of these are discussed. With these recent advances it appears that a rational strategy for achieving a particular stabilized enzyme or protein may be within reach.
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Affiliation(s)
- C O Fágáin
- School of Biological Sciences, Dublin City University, Dublin 9, Ireland
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19
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Kuwajima K, Ikeguchi M, Sugawara T, Hiraoka Y, Sugai S. Kinetics of disulfide bond reduction in alpha-lactalbumin by dithiothreitol and molecular basis of superreactivity of the Cys6-Cys120 disulfide bond. Biochemistry 1990; 29:8240-9. [PMID: 2123714 DOI: 10.1021/bi00488a007] [Citation(s) in RCA: 98] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Kinetics of disulfide reduction in alpha-lactalbumin by dithiothreitol are investigated by measuring time-dependent changes in absorption at 310 nm and in CD ellipticity at 270 nm (pH 8.5 or 7.0, and 25 degrees C). When the disulfide-intact protein is folded, the kinetics are biphasic. The disulfide bond between the half-cystines-6 and -120 is reduced in the fast phase, and the other three disulfide bonds are reduced in the slow phase. The apparent rate constants of the two phases are both proportional to the concentration of dithiothreitol, indicating that both phases are expressed by bimolecular reactions. However, detailed molecular mechanisms that determine the reaction rates are markedly different between the two phases. The slow phase shows a sigmoidal increase in the reaction rate with increasing concentration of a denaturant, urea, and is also accelerated by destabilization of the native state on removal of the bound Ca2+ ion in the protein. The disulfide bonds are apparently protected against the reducing agent in the native structure. The fast phase reaction rate is, however, decreased with an increase in the concentration of urea, and the disulfide bond shows extraordinary superreactivity in native conditions. It is 140 times more reactive than normal disulfides in the fully accessible state, and three-disulfide alpha-lactalbumin produced by the fast phase assumes nativelike structure under a strongly native condition. As ionic strength does not affect the superreactivity of this disulfide bond, electrostatic contributions to the reactivity must be negligible. Inspection of the disulfide bond geometry based on the refined X-ray coordinates of baboon alpha-lactalbumin [Acharya et al. (1989) J. Mol. Biol. 208, 99-127] and comparison of the geometry with those in five other proteins clearly demonstrate that the superreactivity arises from the geometric strain imposed on this disulfide bond by the native structure folding. Relationships of the disulfide strain energy to the protein stability and the disulfide reactivity are discussed.
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Affiliation(s)
- K Kuwajima
- Department of Polymer Science, Faculty of Science, Hokkaido University, Japan
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20
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Remmele RL, McMillan P, Bieber A. Raman spectroscopic studies of hen egg-white lysozyme at high temperatures and pressures. JOURNAL OF PROTEIN CHEMISTRY 1990; 9:475-86. [PMID: 2275757 DOI: 10.1007/bf01024624] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
In situ high-temperature, high-pressure Raman experiments on 3 mM (pH 5) aqueous solutions of hen egg-white (HEW) lysozyme show a decrease in the relative height of the 505 cm-1 band associated with S-S stretching vibrations at 72 degrees C (1 bar). The peak height changes are accompanied by significant band broadening, and the integrated band intensity does not change within experimental error. The effect of increased pressure at 72 degrees C was to hinder broadening of the 505 cm-1 band. HEW lysozyme (2.4 mM, pH 5) was also heated at 76 degrees C, 80 degrees C, and 95 degrees C for different periods of time, and aliquots were quenched to room temperature for Raman and enzymatic activity measurements. After 9 hr at 76 degrees C, the protein exhibits enzyme activity less than 50% of the initial value, and approximately 50% reduction in activity is achieved after 3 hr at 80 degrees C or 1 hr at 95 degrees C. The Raman results suggest that different irreversibly denatured conformations are attained during prolonged exposures at these different temperatures. It is apparent from these studies that the S-S stretch intensity is decreased irreversibly.
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Affiliation(s)
- R L Remmele
- Department of Biochemistry, Colorado State University, Fort Collins 80523
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21
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22
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Pace CN, Grimsley GR, Thomson JA, Barnett BJ. Conformational stability and activity of ribonuclease T1 with zero, one, and two intact disulfide bonds. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37859-1] [Citation(s) in RCA: 170] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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23
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Yang T, Olsen KW. Effects of crosslinking on the thermal stability of hemoglobins. II. The stabilization of met-, cyanomet-, and carbonmonoxyhemoglobins A and S with bis(3,5-dibromosalicyl) fumarate. Arch Biochem Biophys 1988; 261:283-90. [PMID: 3355152 DOI: 10.1016/0003-9861(88)90343-8] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Hemoglobins A and S were crosslinked between Lys 82 beta 1 and Lys 82 beta 2 using bis (3,5-dibromosalicyl) fumarate (J. A. Walder et al. (1979) Biochemistry 18, 4265). Thermal denaturation experiments were used to compare the stabilities of the met, cyanomet, and carbonmonoxy forms of these crosslinked hemoglobins to the corresponding uncrosslinked proteins. Uncrosslinked carbonmonoxy- and cyanomethemoglobins had transition temperatures about 11 degrees C higher than the corresponding met samples. The increase in denaturation temperature (Tm) due to crosslinking was 15 degrees C for the methemoglobins, 10 degrees C for the cyanomethemoglobins, and 4 degrees C for the carbonmonoxy ones. There was no significant difference in stability between the met and carbonmonoxy crosslinked proteins. In order of increasing stability the samples were: met Hb S less than met Hb A less than CO Hb S less than CO Hb A = CN-met Hb A less than met XL-Hb S = CO XL-Hb S less than met XL-Hb A = CO XL-Hb A less than CN-met XL-Hb A. The slight decrease in the stability of Hb S (beta 6 Glu----Val) compared to Hb A can be explained by the replacement of an external ionic group by a hydrophobic residue in Hb S. In mixtures of crosslinked and normal Hb A, the Tm of the uncrosslinked material was slightly increased by the presence of the more stable crosslinked hemoglobin. The effects of both crosslinking and cyanide or carbon monoxide binding can be explained by Le Chatelier's principle since both would favor the native form of the protein.
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Affiliation(s)
- T Yang
- Department of Chemistry, Loyola University of Chicago, Illinois 60626
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24
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25
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Wetzel R, Perry LJ, Baase WA, Becktel WJ. Disulfide bonds and thermal stability in T4 lysozyme. Proc Natl Acad Sci U S A 1988; 85:401-5. [PMID: 3277175 PMCID: PMC279556 DOI: 10.1073/pnas.85.2.401] [Citation(s) in RCA: 106] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Disulfide bonds are thought to serve a stabilizing role in extracellular globular proteins, but little is known about the modes of stabilization or their mechanisms. Thermodynamic data presented here demonstrate that an engineered 3-97 disulfide bond previously shown to stabilize T4 lysozyme in vitro against irreversible thermal inactivation also stabilizes the molecule against reversible thermal unfolding. In this paper, we explore the relationship between the disulfide's thermodynamic contribution to protein folding and its role in providing resistance to irreversible thermal inactivation. In T4 lysozyme (C54V/C97S), a non-crosslinked mutant lacking the two cysteines found in the wild type, sensitivity toward irreversible thermal inactivation increases dramatically at temperatures above the melting temperature of the molecule. In addition, most of the lost activity can be restored by denaturation/renaturation with guanidine hydrochloride. In contrast, the crosslinked mutant T4 lysozyme (13C-97C/C54V) inactivates relatively slowly, even above its melting temperature, and the lost activity is not restored by denaturation/renaturation. These observations suggest that the predominant inactivation pathways for non-crosslinked T4 lysozymes are conformation related, while those for the crosslinked variant are insensitive to the conformational route and thus are susceptible only to slower processes of a chemical nature. We also show that multiple mutants, constructed to contain the 3-97 disulfide plus a temperature-sensitive lesion, are more stable than the wild type to irreversible inactivation even though they are less stable to reversible thermal unfolding. These findings together suggest that the 3-97 disulfide provides stability to irreversible inactivation primarily via a pathway that is independent of its thermodynamic contribution. The 3-97 disulfide may stabilize T4 lysozyme by restricting the unfolded state to a class of more compact structures with less exposed hydrophobic surface, compared to the unfolded states of non-crosslinked T4 lysozymes. The results have implications both for the use of the stabilizing potential of disulfide bonds in protein engineering and for their roles in protein function and evolution.
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Affiliation(s)
- R Wetzel
- Biomolecular Chemistry Department, Genentech, South San Francisco, CA 94080
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26
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Kosower EM. A structural and dynamic model for the nicotinic acetylcholine receptor. EUROPEAN JOURNAL OF BIOCHEMISTRY 1987; 168:431-49. [PMID: 3311748 DOI: 10.1111/j.1432-1033.1987.tb13437.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Folding of the five polypeptide subunits (alpha 2 beta gamma delta) of the nicotinic acetylcholine receptor (AChR) into a functional structural model is described. The principles used to arrange the sequences into a structure include: (1) hydrophobicity----membrane-crossing segments; (2) amphipathic character----ion-carrying segments (ion channel with single group rotations); (3) molecular shape (elongated, pentagonal cylinder)----folding dimensions of exobilayer portion; (4) choice of acetylcholine binding sites----specific folding of exobilayer segments; (5) location of reducible disulfides (near agonist binding site)----additional specification of exobilayer arrangement; (6) genetic homology----consistency of functional group choices; (7) noncompetitive antagonist labeling----arrangement of bilayer helices. The AChR model is divided into three parts: (a) exobilayer consisting of 11 antiparallel beta-strands from each subunit; (b) bilayer consisting of four hydrophobic and one amphiphilic alpha-helix from each subunit; (c) cytoplasmic consisting of one (folded) loop from each subunit. The exobilayer strands can form a closed 'flower' (the 'resting state') which is opened ('activated') by agonists bound perpendicular to the strands. Rearrangement of the agonists to a strand-parallel position and partial closing of the 'flower' leads to a desensitized receptor. The actions of acetylcholine and succinoyl and suberoyl bis-cholines are clarified by the model. The opening and closing of the exobilayer 'flower' controls access to the ion channel which is composed of the five amphiphilic bilayer helices. A molecular mechanism for ion flow in the channel is given. Openings interrupted by short duration closings (50 microseconds) depend upon channel group motions. The unusual photolabeling of intrabilayer serines in alpha, beta and delta subunits but not in gamma subunits near the binding site for non-competitive antagonists is explained along with a mechanism for the action of these antagonists such as phencyclidine. The unusual alpha 192Cys-193Cys disulfide may have a special peptide arrangement, such as a cis-peptide bond to a following proline (G.A. Petsko and E.M. Kosower, unpublished results). The position of phosphorylatable sites and proline-rich segments are noted for the cytoplasmic loops. The dynamic behavior of the AChR channel and many different experimental results can be interpreted in terms of the model. An example is the lowering of ionic conductivity on substitution of bovine for Torpedo delta M2 segment. The model represents a useful construct for the design of experiments on AChR.
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Affiliation(s)
- E M Kosower
- Biophysical Organic Chemistry Unit, School of Chemistry, Sackler Faculty of Exact Sciences, Tel-Aviv University, Israel
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White FL, Olsen KW. Effects of crosslinking on the thermal stability of hemoglobin. I. The use of bis(3,5-dibromosalicyl) fumarate. Arch Biochem Biophys 1987; 258:51-7. [PMID: 3662541 DOI: 10.1016/0003-9861(87)90321-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The double-headed aspirin, bis(3,5-dibromosalicyl) fumarate, has been used to crosslink hemoglobin A between Lys 82 beta 1 and Lys 82 beta 2 (J. A. Walder et al. (1979) Biochemistry 18,4265). Denaturation experiments were used to compare the stability of this crosslinked protein to that of hemoglobin A. Thermal denaturations, done in 0.01 M 4-morpholine-propanesulfonic acid, pH 7, containing 0.9 M guanidine to prevent precipitation at high temperatures, were monitored by changes in absorbance between 190 and 650 nm using a diode array spectrophotometer. The sample was heated from 25 to 70 degrees C at 0.3 degrees C/min. The data were analyzed by using both a two-state model and a novel first derivative method. As expected, methemoglobin A had a single, broad transition with a midpoint of 40.7 degrees C. The crosslinked methemoglobin showed a transition at 57.1 degrees C. Two minor transitions, one of which was apparently due to residual unmodified hemoglobin, were also observed in the crosslinked sample. Thus, a single crosslink between only two of the four subunits can lead to a significantly more stable molecule. These results can be explained by Le Chatelier's principle, since crosslinking prevents dissociation of the beta-subunits and, thereby, holds the entire tetramer together.
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Affiliation(s)
- F L White
- Department of Chemistry, Loyola University of Chicago, Illinois 60626
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28
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Intramolecular cross-linking of domains at the active site links A1 and B subfragments of the Ca2+-ATPase of sarcoplasmic reticulum. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)61615-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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29
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Katz BA, Kossiakoff A. The crystallographically determined structures of atypical strained disulfides engineered into subtilisin. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)66737-7] [Citation(s) in RCA: 75] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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30
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Kuroki R, Yamada H, Moriyama T, Imoto T. Chemical mutations of the catalytic carboxyl groups in lysozyme to the corresponding amides. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(18)67057-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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31
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Comparison of intramolecular and intermolecular reactions in protein folding. ACTA ACUST UNITED AC 1986. [DOI: 10.1007/bf01025582] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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