US4304853A
Expired / Lapsed
US
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Method of determination for proteases and antiproteases
Assignee: Individual
•
Filing: 1980-04-22
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Granted: 1981-12-08
•
Expires: 2000-04-22
Abstract
Abstract A method for the determination of proteases and antiproteases, especially those of the blood clotting system and of the complement, is described, according to which a fragment liberated from a substrate by enzymatic hydrolysis is determined electrochemically.
Inventors
- 👤 Marcel Jozefonvicz
- 👤 Jean M. Nigretto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 02:34
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/56; C12Q2337/00; C12Q2337/10
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
99 words
A method for the determination of a protease which comprises reacting said protease with a substrate of the formula A-B, wherein A is N-substituted arginyl or a peptide having a C-terminal arginyl group and B is the residue of an amine electrolytically active amine, B-H, which can be oxidized or reduced electrochemically, whereby said amine is released from said substrate, and the determining the amount of amine which has been released by measuring an electric oxidation or reduction current passed between electrodes immersed in a medium containing said released amine, one of which electrodes is a pre-conditioned measurement electrode.
Claim 2
Independent Claim
99 words
A method for the determination of a protease which comprises reacting said protease with a substrate of the formula A-B, wherein A is N-substituted arginyl or a peptide having a C-terminal arginyl group and B is the residue of an amine electrolytically active amine, B-H, which can be oxidized or reduced electrochemically, whereby said amine is released from said substrate, and the determining the amount of amine which has been released by measuring an electric oxidation or reduction current passed between electrodes immersed in a medium containing said released amine, one of which electrodes is a pre-conditioned measurement electrode.
Claim 3
Dependent Claim
19 words
A method as in claim 1 wherein said protease is a blood clotting system protease or a complement protease.
Claim 4
Dependent Claim
17 words
A method as in claim 1 wherein said electrodes include said measurement electrode and a reference electrode.
Claim 5
Dependent Claim
15 words
A method as in claim 3 wherein said measurment electrode is a noble metal electrode.
Claim 6
Dependent Claim
24 words
A method as in claim 3 wherein said measurement electrode is a carbon paste electrode made by mixing carbon powder with a paraffin oil.
Claim 7
Dependent Claim
23 words
A method as in claim 1 wherein an auxiliary electrode is additionally present immersed in said medium to ensure the passage of current.
Claim 8
Dependent Claim
25 words
A method as in claim 1 wherein said electric oxidation or reduction current is measured at intervals to detect concentration changes for said amine, B-H.
Claim 9
Dependent Claim
40 words
A method as in claim 7 wherein said electric oxidation or reduction current is measured by applying a potential having a saw-tooth profile to said electrodes to produce a current/voltage characteristic having a peak value, and determining said peak value.
Claim 10
Dependent Claim
13 words
A method as in claim 1 wherein said medium is a heterogeneous medium.
Claim 11
Dependent Claim
13 words
A method as in claim 9 wherein said heterogeneous medium is whole blood.
Claim 12
Dependent Claim
13 words
A method as in claim 1 wherein said medium is an aqueous medium.
Claim 13
Dependent Claim
18 words
A method as in claim 11 wherein said aqueous medium comprises from 2 to 10 percent of dimethylsulfoxide.
Claim 14
Dependent Claim
13 words
A method as in claim 1 wherein said medium is a non-aqueous medium.
Claim 15
Dependent Claim
17 words
A method as in claim 1 wherein said released amine is isolated prior to determining its amount.
Claim 16
Dependent Claim
25 words
A method as in claim 1 wherein said amine B-H is a member selected from the group consisting of aromatic and heterocyclic amines and polyamines.
Claim 17
Dependent Claim
21 words
A method as in claim 15 wherein said amine is selected from the group consisting of p-amino-diphenylamine, 4,4'-benzidine, o-anisidine,4-methoxy-2-naphthylamine, and p-nitroaniline.
Claim 18
Dependent Claim
23 words
A method as in claim 1 wherein said substrate is activated by the presence therein of an acyl, sulfonyl, tosyl, or benzoyl group.
Claim 19
Dependent Claim
16 words
A method as in claim 1 wherein said substrate is benzoyl-arginyl, tosyl-arginyl, tosyl-L-glycyl-L-prolyl-L-arginyl,H-D-phenylalanyl-L-pipecolyl-L-arginyl, N-benzoyl-L-phenylalanyl-L-valyl-L-arginyl, or H-D-phenylalanyl-L-pipecolyl-L-arginyl.
Claim 20
Dependent Claim
24 words
A method as in claim 1 wherein said electrolytically active amine is p-amino-diphenylamine and said medium is buffered and has a pH of 8.15.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-12-07 | 1985-06-08 | 1985-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-12-07 | 1989-06-08 | 1989-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-12-07 | 1993-06-08 | 1993-12-08 | $7700.00 | Window Closed / Lapsed |