US5008205A
Expired / Lapsed
US
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Method of facilitating detection of amino acid derivatives with enhanced sensitivity
Assignee: APPLIED PROTEIN TECHNOLOGIES Inc 103 BROOKLINE STREET CAMBRIDGE
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Filing: 1988-08-10
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Granted: 1991-04-16
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Expires: 2008-08-10
Abstract
Abstract A method of detecting and identifying amino acid derivatives produced by sequential cleavage of N-terminal residues from a polypeptide chain. The polypeptide is first reacted with an isothiocyanate to produce an N-terminal-thiocarbamyl polypeptide. This derivative is then cleaved to form a cyclic ATZ derivative, which is subsequently combined with a detectable alcohol in anhydrous acid to primarily produce a stable thiocarbamyl amino acid ester. This compound may be readily detected and identified.
Inventors
- 👤 Marcus J. Horn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:53
CPC Classifications
G; G01; G01N; G01N33/00; G01N33/48; G01N33/50; G01N33/68; G01N33/6803; G01N33/6818; G01N33/6824; Y; Y10; Y10T; Y10T436/00; Y10T436/14; Y10T436/141111; Y10T436/25
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
51 words
A method of enhancing the detectability of an amino acid in order to facilitate identification, comprising the steps of converting the amino acid to a 5-thiazolinone amino acid derivative and reacting the derivative with a mixture of an anhydrous acid and an alcohol to primarily produce a thiocarbamyl amino acid ester.
Claim 2
Independent Claim
51 words
A method of enhancing the detectability of an amino acid in order to facilitate identification, comprising the steps of converting the amino acid to a 5-thiazolinone amino acid derivative and reacting the derivative with a mixture of an anhydrous acid and an alcohol to primarily produce a thiocarbamyl amino acid ester.
Claim 3
Dependent Claim
12 words
The method of claim 1 in which said acid comprises hydrochloric acid.
Claim 4
Dependent Claim
12 words
The method of claim 1 in which said alcohol comprises fluorenemethyl alcohol.
Claim 5
Dependent Claim
11 words
The method of claim 1 in which said alcohol comprises ]-anthracenemethanol.
Claim 6
Dependent Claim
18 words
The method of claim 1 wherein the amino acid derivative is obtained using a sequential chemical degradative procedure.
Claim 7
Dependent Claim
13 words
The method of claim 5 wherein the degradative procedure utilizes an isothiocyanate compound.
Claim 8
Dependent Claim
11 words
The method of claim 6 wherein the isothiocyanate compound is phenylisothiocyanate.
Claim 9
Dependent Claim
10 words
The method of claim 1 wherein the alcohol is colored.
Claim 10
Dependent Claim
10 words
The method of claim 1 wherein the alcohol is fluorescent.
Claim 11
Dependent Claim
11 words
The method of claim 1 wherein the alcohol is electrochemically active.
Claim 12
Dependent Claim
10 words
The method of claim 1 wherein the alcohol is radiolabeled.
Claim 13
Independent Claim
80 words
A method of determining the identity of the N-terminal amino acid of a polypeptide, comprising the steps of: a. reacting the polypeptide with PITC to form an N-terminal-PTC derivative of the polypeptide; b. cleaving the N-terminal-PTC amino acid from the remainder of the polypeptide to form a cyclic ATZ derivative; c. reacting the cyclic ATZ derivative with a detectable alcohol in anhydrous acid to primarily produce a PTC amino acid ester; d. detecting and identifying the PTC amino acid ester.
Claim 14
Independent Claim
80 words
A method of determining the identity of the N-terminal amino acid of a polypeptide, comprising the steps of: a. reacting the polypeptide with PITC to form an N-terminal-PTC derivative of the polypeptide; b. cleaving the N-terminal-PTC amino acid from the remainder of the polypeptide to form a cyclic ATZ derivative; c. reacting the cyclic ATZ derivative with a detectable alcohol in anhydrous acid to primarily produce a PTC amino acid ester; d. detecting and identifying the PTC amino acid ester.
Claim 15
Dependent Claim
20 words
The method of claim 12 wherein the PTC amino acid ester is primarily produced by using a sterically hindered alcohol.
Claim 16
Dependent Claim
33 words
The method of claim 12 wherein the PTC amino acid ester is primarily produced by using an alcohol that, when combined with the cyclic ATZ, disfavors rearrangement to the cyclic conformation of PTH.
References Cited (Backward Citations)
US4865994A
Cited
US4863870A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1994-04-15 | 1994-10-15 | 1995-04-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1998-04-15 | 1998-10-15 | 1999-04-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2002-04-15 | 2002-10-15 | 2003-04-16 | $7700.00 | Window Closed / Lapsed |