The electroreduction of the disulphide bonds of insulin and other proteins

Cecil, R.; Weitzman, P.D.J.

doi:10.1042/bj0930001

Cited by 121 publications

(47 citation statements)

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“…But the detailed mechanism of the B-chain/ domain exerting its effect is still unknown. The intra A-domain disulfide of IGF-1 is a strained bond with high energetic state (33) while the intra A-chain disulfide of insulin is a stable bond (44). The different energetic state of the intra A-chain/domain disulfide is probably relevant to their different folding property: insulin/PIP folds into one unique structure while IGF-1 folds into two disulfide isomers.…”

Section: Discussionmentioning

confidence: 99%

“…In the redox buffer that favors the disulfide formation for most proteins this disulfide can be reduced. However, the intra A-chain disulfide, A6-A11, of insulin was a stable bond (44). The different energetic state of the intra A-chain/ domain disulfide probably led to the different folding behavior of insulin and IGF-1.…”

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confidence: 99%

“…The three-dimensional structure of IGF-1 is very similar with that of insulin (7). The architecture of insulin and IGF-1 mainly consists of three R-helical segments (A2-A8, A13-A19, and B9-B19 in insulin; [8][9][10][11][12][13][14][15][16][17][18][42][43][44][45][46][47][48][49], and 54-61 in IGF-1) in the A-and B-chain/domains ( Figure 1A,B). The three R-helical segments are stabilized by the three disulfides (A6-A11, A7-B7, A20-B19 in insulin; 47-52, 6-48, 18-61 in IGF-1) (8)(9)(10).…”

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The Different Energetic State of the Intra A-Chain/Domain Disulfide of Insulin and Insulin-like Growth Factor 1 Is Mainly Controlled by Their B-Chain/Domain

2002

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Insulin and insulin-like growth factor 1 (IGF-1) share homologous sequence, similar threedimensional structure, and weakly overlapping biological activity, but different folding information is stored in their homologous sequences: the sequence of insulin encodes one unique thermodynamically stable three-dimensional structure while that of IGF-1 encodes two disulfide isomers with different threedimensional structure but similar thermodynamic stability. Their different folding behavior probably resulted from the different energetic state of the intra A-chain/domain disulfide: the intra A-chain disulfide of insulin is a stable bond while that of IGF-1 is a strained bond with high energy. To find out the sequence determinant of the different energetic state of their intra A-chain/domain disulfide, the following experiments were carried out. First, a local chimeric single-chain insulin (PIP) with the A8-A10 residues replaced by the corresponding residues of IGF-1 was prepared. Second, the disulfide stability of two global hybrids of insulin and IGF-1, Ins(A)/IGF-1(B) and Ins(B)/IGF-1(A), was investigated. The local segment swap had no effect on the fidelity of disulfide pairing and the disulfide stability of PIP molecule although the swapped segment is close to the intra A-chain/domain disulfide. In redox buffer which favors the disulfide formation for most proteins, Ins(A)/IGF-1(B) cannot form and maintain its native disulfides just like that of IGF-1, while the disulfides of Ins(B)/IGF-1(A) are stable in the same condition. One major equilibrium intermediate with two disulfides of Ins(A)/IGF-1(B) was purified and characterized. V8 endoproteinase cleavage and circular dichroism analysis suggested that the intra A-chain/domain disulfide was reduced in the intermediate. Our present results suggested that the energetic state of the intra A-chain/domain disulfide of insulin and IGF-1 was not controlled by the A-chain/domain sequence close to this disulfide but was mainly controlled by the sequence of the B-chain/domain.Insulin is an extensively studied small globular protein with A-and B-chains linked by three disulfides (one intrachain bond, A6-A11; two interchain bonds, A7-B7 and A20-B19). Its three-dimensional structure has been well-defined by X-ray crystallography (1, 2) and NMR (3-5) since the 1970s. IGF-1 1 is an insulin-like 70-residue singlechain protein composed of B-, C-, A-, and D-domains (6). The B-and A-domains of IGF-1 are homologous to the Band A-chains of insulin, respectively; the C-domain is analogous to the C-peptide of proinsulin, but they share no sequence homology; the D-domain has no counterparts in insulins. The three-dimensional structure of IGF-1 is very similar with that of insulin (7). The architecture of insulin and IGF-1 mainly consists of three R-helical segments (A2-A8, A13-A19, and B9-B19 in insulin; 8-18, 42-49, and 54-61 in IGF-1) in the A-and B-chain/domains ( Figure 1A,B). The three R-helical segments are stabilized by the three disulfides (A6-A11, A7-B7, A20-B19 in insul...

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Section: Discussionmentioning

confidence: 99%

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confidence: 99%

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confidence: 99%

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The Different Energetic State of the Intra A-Chain/Domain Disulfide of Insulin and Insulin-like Growth Factor 1 Is Mainly Controlled by Their B-Chain/Domain

2002

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“…Insulin, lysozyme and trypsin contain, respectively, 3, 4 and 6 disulphide bonds per molecule, and other experimental evidence (see, e.g., Cecil & Wake, 1962;Cecil & Weitzman, 1964) suggests that at least some of these bonds are readily accessible and sensitive to cleavage reagents. Their non-reactivity to thionitrobenzoate, even in 4M-urea, is therefore unlikely to be due to unusual stability.…”

Section: Resultsmentioning

confidence: 99%

Evidence against the proposed interaction of thionitrobenzoate with protein disulphide bonds

1975

Biochemical Journal

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“…The most prominent one is the electroreduction of disulfide bridges between cysteines [70] (two joined-up cysteines are sometimes called cystines) to dithiols:…”

Section: Transductionmentioning

confidence: 99%

Molecular recognition in olfaction

Horsfield

Haase

Turin

2017

Advances in Physics: X

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The mechanism by which the chemical identity of odourants is established by olfactory receptors is a matter of intense debate. Here we present an overview of recent ideas and data with a view to summarising what is known, and what has yet to be determined. We outline the competing theories, and summarise experimental results employing isotopes obtained for mammals, insects, and individual receptors that enable us to judge the relative correctness of the theories. ARTICLE HISTORY

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The electroreduction of the disulphide bonds of insulin and other proteins

Cited by 121 publications

References 22 publications

The Different Energetic State of the Intra A-Chain/Domain Disulfide of Insulin and Insulin-like Growth Factor 1 Is Mainly Controlled by Their B-Chain/Domain

The Different Energetic State of the Intra A-Chain/Domain Disulfide of Insulin and Insulin-like Growth Factor 1 Is Mainly Controlled by Their B-Chain/Domain

Evidence against the proposed interaction of thionitrobenzoate with protein disulphide bonds

Molecular recognition in olfaction

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