US4837165A
Expired / Lapsed
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Method for sequencing of peptides by carboxyl terminus degradation
Assignee: City of Hope
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Filing: 1988-04-20
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Granted: 1989-06-06
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Expires: 2008-04-20
Abstract
Abstract A peptide is sequenced from its carboxyl terminal by coupling with an isothiocyanate having a chemical formula R(x)Si(NCS)y where x=0-3 and y=1-4. R may be alkyl or aryl. The coupling reaction is preferably conducted at a temperature range of 50 DEG -90 DEG C. for a period to approximately sixty (60) minutes or less. A weak acid anhydride, preferably a carboxylic acid anhydride, or a weak acid chloride, preferably a carboxylic acid chloride, may be mixed with the isothiocyanate. An organic base catalyst selected from a group consisting of tertiary amines including aromatic amines such as pyridine may also be utilized.
Inventors
- 👤 David H. Hawke
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-10 02:11
CPC Classifications
C; C07; C07K; C07K1/00; C07K1/06; C07K1/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
84 words
In a method for sequencing a peptide by carboxyl terminal degradation which comprises coupling the carboxyl terminus of a peptide with a coupling reagent to form a peptidyl thiohydantoin derivative, cleaving the peptidyl thiohydantoin derivative to provide a thiohydantoin derivative of the amino acid previously at the carboxyl terminus of the peptide and a peptidyl residue lacking such an amino acid, and identifying the amino acid in the amino acid thiohydantoin derivative, wherein the improvement comrprises utilizing a silyl isothiocyanate as the coupling reagent.
Claim 2
Dependent Claim
84 words
In a method for sequencing a peptide by carboxyl terminal degradation which comprises coupling the carboxyl terminus of a peptide with a coupling reagent to form a peptidyl thiohydantoin derivative, cleaving the peptidyl thiohydantoin derivative to provide a thiohydantoin derivative of the amino acid previously at the carboxyl terminus of the peptide and a peptidyl residue lacking such an amino acid, and identifying the amino acid in the amino acid thiohydantoin derivative, wherein the improvement comrprises utilizing a silyl isothiocyanate as the coupling reagent.
Claim 3
Dependent Claim
35 words
The method of claim 1 in which the isothiocyanate has the formula R.sub.(x) Si(NCS) y where x is 0 to 3, y is 1 to 4 and R is an alkyl or an aryl substituent.
Claim 4
Dependent Claim
12 words
The method of claim 2 in which the isothiocyanate is trimethylsilyl isothiocyanate.
Claim 5
Dependent Claim
15 words
The method of claim 2 in which a catalyst is included in the coupling reagent.
Claim 6
Dependent Claim
13 words
The method of claim 4 in which the catalyst is a tertiary amine.
Claim 7
Dependent Claim
11 words
The method of claim 4 in which the catalyst is pyridine.
Claim 8
Dependent Claim
18 words
The method of claim 2 in which a weak organic acid anhydride is included in the coupling reagent.
Claim 9
Dependent Claim
15 words
The method of claim 7 in which the weak organic acid anhydride is acetic anhydride.
References Cited (Backward Citations)
US4065412A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |