Enzymatic cycling method using creatine kinase to measure creatine by real-time detection
Shigeru Ueda1, Shin-Ichi Sakasegawa1
1R&D Group, Diagnostics Department, Asahi Kasei Pharma Corporation, Izunokuni-shi, Shizuoka 410-2321, Japan.
Analytical Biochemistry
|May 14, 2016
Summary
A new enzymatic assay using creatine kinase (CK) accurately measures creatine and creatinine. This sensitive method offers high precision for clinical diagnostics and kidney function assessment.
Area of Science:
- Biochemistry
- Enzymology
- Clinical Diagnostics
Background:
- Creatine kinase (CK) plays a crucial role in cellular energy metabolism.
- Accurate measurement of creatine and creatinine is vital for assessing kidney function.
- Existing assays may lack the sensitivity or specificity required for certain clinical applications.
Purpose of the Study:
- To develop a novel, highly sensitive enzymatic cycling method for creatine measurement.
- To adapt this method for the quantitative assay of creatinine, a key kidney function marker.
Main Methods:
- Utilized the reversible nature of the creatine kinase (CK) reaction.
- Employed excess ATP and IDP to drive forward and reverse reactions, respectively.
- Real-time detection via ADP-dependent glucokinase (ADP-GK) and glucose-6-phosphate dehydrogenase, monitoring NADP reduction at 340 nm.
Main Results:
- The enzymatic cycling method demonstrated high sensitivity, with signal output proportional to CK concentration.
- Successfully adapted the CK-based assay with creatinine amidohydrolase to quantify creatinine.
- The assay confirmed its quantitative capability for creatinine measurement.
Conclusions:
- The developed enzymatic cycling assay provides a sensitive and quantitative method for creatine and creatinine determination.
- This novel approach holds promise for improved clinical diagnostics, particularly in kidney function assessment.
- The method's high sensitivity makes it suitable for assays requiring precise analyte quantification.
