US4216141A
Expired / Lapsed
US
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Method for cyclization of peptides
Assignee: Salk Institute for Biological Studies
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Filing: 1978-07-19
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Granted: 1980-08-05
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Expires: 1998-07-19
Abstract
Abstract Peptides containing a disulfide bond between two cysteine residues are formed by an oxidation process. The oxidation step is accomplished under conditions whereby the sulfhydryl concentration in a reaction mixture is maintained at substantially zero during the reaction. In the process, an aqueous solution of a peptide containing at least one pair of cysteine moities is added incrementally to a buffered solution containing an oxidizing agent. The period between addition of the increments of the peptide solution is sufficient that the reaction to form the disulfide bond occurs substantially instantaneously. The increments are of such size that the sulfhydryl concentration during the reaction remains substantially constant and at a level of substantially zero, equivalent to infinite dilution.
Inventors
- 👤 Jean E. F. Rivier
- 👤 Robert F. Galyean
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 12:14
CPC Classifications
C; C07; C07K; C07K1/00; C07K1/12; C07K1/06; C07K1/061; C07K1/067; Y; Y10; Y10S; Y10S930/00; Y10S930/01; Y10S930/15; Y10S930/16
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
130 words
A method for forming a disulfide bridge in peptides containing at least one pair of cysteine moieties comprising preparing a solution of a peptide containing at least one pair of cysteine moieties, preparing a solution of an oxidizing agent, adding said peptide solution in increments to said solution of oxidizing agent, monitoring the pH of the reaction mixture comprising the solution of oxidizing agent and the increment of the peptide solution and maintaining the pH of the reaction mixture at a level of from about 6 to about 8, the period between addition and the size of said increments being such that the oxidizing reaction to form the disulfide bond occurs substantially instantaneously and the sulfhydryl concentration during the reaction remains substantially constant and at a level of substantially zero.
Claim 2
Independent Claim
130 words
A method for forming a disulfide bridge in peptides containing at least one pair of cysteine moieties comprising preparing a solution of a peptide containing at least one pair of cysteine moieties, preparing a solution of an oxidizing agent, adding said peptide solution in increments to said solution of oxidizing agent, monitoring the pH of the reaction mixture comprising the solution of oxidizing agent and the increment of the peptide solution and maintaining the pH of the reaction mixture at a level of from about 6 to about 8, the period between addition and the size of said increments being such that the oxidizing reaction to form the disulfide bond occurs substantially instantaneously and the sulfhydryl concentration during the reaction remains substantially constant and at a level of substantially zero.
Claim 3
Dependent Claim
37 words
A method in accordance with claim 1, wherein the pH of the peptide solution is maintained at a level of less than about 5 prior to addition of the peptide solution to the solution of oxidizing agent.
Claim 4
Dependent Claim
22 words
A method in accordance with claim 1, wherein said pH is monitored at a level of from about 6.5 to about 7.5.
Claim 5
Dependent Claim
15 words
A method in accordance with claim 1, wherein said oxidizing agent is a ferricyanide salt.
Claim 6
Dependent Claim
22 words
A method in accordance with claim 1, wherein said peptide is selected from the group consisting of somatostatin and analogs of somatostatin.
Claim 7
Dependent Claim
18 words
A method in accordance with claim 1, wherein said peptide is selected from vasopressin and analogs of vasopressin.
Claim 8
Dependent Claim
22 words
A method in accordance with claim 1, wherein said peptide is selected from the group consisting of oxytocin and analogs of oxytocin.
Claim 9
Dependent Claim
22 words
A method in accordance with claim 1, wherein said peptide is selected from the group consisting of calcitonins and analogs of calcitonins.
Claim 10
Dependent Claim
19 words
A method in accordance with claim 1, wherein the sulfhydryl group of said cysteine moieties is generated in situ.
Claim 11
Dependent Claim
42 words
A method in accordance with claim 9, wherein said sulfhydryl groups of said cysteine moieties are protected in the form of the silver salt and said oxidizing solution contains chloride ions to deprotect said sulfhydryl groups and generate sulfhydryl groups in situ.
Claim 12
Dependent Claim
43 words
A method in accordance with claim 9, wherein said sulfhydryl groups of said cysteine moieties are protected in the form of the mercury salt and said oxidizing solution contains sulfide ions to deprotect said sulfhydryl groups and form said sulfhydryl groups in situ.
Claim 13
Dependent Claim
13 words
A method in accordance with claim 1, wherein said oxidizing solution contains methanol.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-08-05 | 1984-02-04 | 1984-08-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-08-05 | 1988-02-04 | 1988-08-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-08-05 | 1992-02-04 | 1992-08-05 | $7700.00 | Window Closed / Lapsed |