US3907644A
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Creatinine amidohydrolase composition and process for the determination of creatinine
Assignee: Roche Diagnostics GmbH
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Filing: 1973-11-13
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Granted: 1975-09-23
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Expires: 1993-11-13
Abstract
Abstract Creatinine is determined by use of a novel enzyme, creatinine amidohydrolase, which converts the creatinine in a creatininecontaining sample to creatine, the latter being determined in conventional manner as a measure of the creatinine originally present. The ability of the enzyme to convert creatinine to creatine can also be utilized to monitor the efficacy of enrichment processes for recoverying the enzyme, by sampling the product of each step of such process and determining its ability to convert excess creatinine added thereto to creatine, as a measure of the activity of the enzyme present in such product.
Inventors
- 👤 Hans Mollering
- 👤 Klaus Beaucamp
- 👤 Michael Nelboeck-Hochstetter
- 👤 Hans Ulrich Bergmeyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 14:36
CPC Classifications
C; C12; C12Q; C12Q1/00; C12Q1/34; C12N; C12N9/00; C12N9/14; C12N9/78; C12N9/86; C12Q1/48; C12Q1/50; G; G01; G01N; G01N2333/00; G01N2333/90; G01N2333/91; G01N2333/912; G01N2333/91205; G01N2333/9123; G01N2333/914; G01N2333/978; G01N2333/986; Y; Y10; Y10S; Y10S435/00; Y10S435/814; Y10S435/815; Y10S435/816; Y10S435/8215; Y10S435/822; Y10S435/824; Y10S435/829; Y10S435/911; Y10S435/933
Claims Analysis
Total Claims: 29
Claim 1
Independent Claim
36 words
PROCESS FOR THE DETERMINATION OF CREATININE, WHICH PROCESS COMPRISES INCUBATING A CREATININE-CONTAINING SAMPLE WITH CREATININE AMIDOHYDROLASE AT A PH ABOVE 7 AND DETERMINING THE CREATINE FORMED AS A MEASURE OF THE CREATININE PRESENT IN THE SAMPLE.
Claim 2
Dependent Claim
36 words
PROCESS FOR THE DETERMINATION OF CREATININE, WHICH PROCESS COMPRISES INCUBATING A CREATININE-CONTAINING SAMPLE WITH CREATININE AMIDOHYDROLASE AT A PH ABOVE 7 AND DETERMINING THE CREATINE FORMED AS A MEASURE OF THE CREATININE PRESENT IN THE SAMPLE.
Claim 3
Dependent Claim
70 words
Process as claimed in claim 1 wherein the creatine formed is determined by the addition of adenosine triphosphate and creatine kinase to result in conversion of the creatine into creatine phosphate and adenosine diphosphate, whereupon the adenosine diphosphate formed in converted into adenosine triphosphate with pyruvate kinase and lactate dehydrogenase as well as phosphoenol pyruvate, with the consumption of NADH being measured optically aS a measure of the creatine present.
Claim 4
Dependent Claim
69 words
Method of monitoring the efficacy of a process for enriching creatinine amidohydrolase in a mixture containing same by conventional purification or enrichment processes, which method comprises taking a sample of the fraction obtained after a conventional purification step, adding an excess or creatinine thereto, and measuring the ability of said sample to convert the added creatinine into creatine as a measure of the creatinine amidohydrolase present in said sample.
Claim 5
Dependent Claim
69 words
Method of monitoring the efficacy of a process for enriching creatinine amidohydrolase in a mixture containing same by conventional purification or enrichment processes, which method comprises taking a sample of the fraction obtained after a conventional purification step, adding an excess or creatinine thereto, and measuring the ability of said sample to convert the added creatinine into creatine as a measure of the creatinine amidohydrolase present in said sample.
Claim 6
Dependent Claim
20 words
Method as claimed in claim 3 wherein the conventional purification step is carried out at a pH of above 7.
Claim 7
Dependent Claim
13 words
Method as claimed in claim 3 wherein said purification step is exchange chromatography.
Claim 8
Dependent Claim
28 words
Method as claimed in claim 3 wherein the purification step comprises mechanical digestion by means of high pressure dispersion or by use of a digestion mill or ultrasound.
Claim 9
Dependent Claim
25 words
Method as claimed in claim 3 wherein said purification step comprises high pressure dispersion carried out at a pressure of from 700 to 800 atmospheres.
Claim 10
Dependent Claim
19 words
Method as claimed in claim 3 wherein said purification step comprises digestion at a pH value of about 8.0.
Claim 11
Dependent Claim
13 words
Method as claimed in claim 3 wherein said purification step comprises polyanion fractionation.
Claim 12
Dependent Claim
25 words
Method as claimed in claim 7 wherein said polyanion fractionation is carried out by way of polyethyleneimine precipitation at a buffer concentration of about 0.1M.
Claim 13
Dependent Claim
13 words
Method as claimed in claim 3 wherein said purification step comprises isopropanol fractionation.
Claim 14
Dependent Claim
20 words
Method as claimed in claim 11 wherein said isopropanol fractionation is carried out with 90 percent isopropanol at about 25*C.
Claim 15
Dependent Claim
56 words
Method as claimed in claim 3 wherein said purification or enrichment process comprises adsorbing the mixture containing creatinine amidohydrolase on a weakly basic ion exchanger at an ion concentration below 0.1M, the exchanger is washed with about 0.1M buffer and creatinine amidohydrolase and creatine amidinohydrolase are eluted with an ion concentration of 0.2M and 0.5M, respectively.
Claim 16
Dependent Claim
25 words
Method as claimed in claim 13 wherein the enzymes are adsorbed on the weakly basic ion exchanger at an ion concentration of 0.01 to 0.05M.
Claim 17
Dependent Claim
52 words
Method for the specific determination of creatinine in the form of an aqueous solution thereof, which process comprises incubating said aqueous creatinine-containing solution with cratinine amidohydrolase at a pH value from about 7.5 to 9 and determining either the creatine formed or the decrease of creatinine content caused by the incubation reaction.
Claim 18
Dependent Claim
52 words
Method for the specific determination of creatinine in the form of an aqueous solution thereof, which process comprises incubating said aqueous creatinine-containing solution with cratinine amidohydrolase at a pH value from about 7.5 to 9 and determining either the creatine formed or the decrease of creatinine content caused by the incubation reaction.
Claim 19
Dependent Claim
45 words
Method as claimed in claim 15 wherein said incubation is carried out in a phosphate or pyrophosphate buffer and the resulting mixture is treated with picric acid and aqueous sodium hydroxide to produce a coloration which is taken as a measure of the creatinine difference.
Claim 20
Dependent Claim
27 words
Method as claimed in claim 15 wherein the creatine formed is determined by phosphorylation with creatine kinase and adenosine triphosphate and measurement of the adenosine diphosphate formed.
Claim 21
Dependent Claim
31 words
Method as claimed in claim 15 wherein the creatine formed is decomposed in the presence of creatinase, with the formation of urea, and the urea formed is determined in known manner.
Claim 22
Dependent Claim
15 words
Method as claimed in claim 15 wherein said pH value is from 7.8 to 8.3.
Claim 23
Dependent Claim
27 words
Method as claimed in claim 15 wherein the creatinine-containing solution to be determined in deproteinized and the creatine formed is measured with the use of creatine kinase.
Claim 24
Dependent Claim
16 words
Method as claimed in claim 15 wherein said creatinine amidohydrolase is used in admixture with creatinase.
Claim 25
Dependent Claim
27 words
REAGENT COMPOSITION FOR THE SPECIFIC DETERMINATION OF CREATININE, WHICH STANDARD A. A CREATININE STANDARD B. PICRIC ACID C. AN AQUEOUS SOLUTION OF SODIUM HYDROXIDE D. CREATININE AMIDOHYDROLASE
Claim 26
Dependent Claim
27 words
REAGENT COMPOSITION FOR THE SPECIFIC DETERMINATION OF CREATININE, WHICH STANDARD A. A CREATININE STANDARD B. PICRIC ACID C. AN AQUEOUS SOLUTION OF SODIUM HYDROXIDE D. CREATININE AMIDOHYDROLASE
Claim 27
Dependent Claim
17 words
Composition as claimed in claim 22 wherein the said creatiNine amidohydrolase is an admixture with a buffer.
Claim 28
Dependent Claim
15 words
Composition as claimed in claim 22 wherein said creatinine amidohydrolase is an admixture with amidinohydrolase.
Claim 29
Dependent Claim
30 words
Reagent composition as claimed in claim 22 comprising: a. buffer, NADH, ATP and phosphoenol pyruvate b. lactate dehydrogenase, pyruvate kinase and magnesium chloride. c. creatine kinase and d. creatinine amidohydrolase.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |