8-quinolyl phosphate as a substrate for the fluorimetric determination of alkaline phosphatase.
BACKGROUND
Alkaline phosphatase (ALP) is an important target for clinical analysis. 8-Quinolyl phosphate (QP) was developed as a new substrate for the fluorimetric determination of ALP activity.


METHODS
QP is a strong fluorescent substance and the product of the enzyme reaction is 8-hydroxyquinoline (HQ), which has no fluorescence. Under the optimal conditions for the determination of ALP, the decreased fluorescence intensity via the enzyme reaction is proportional to ALP activity. The fluorescence intensity was measured at lambdaex/lambdaem=318/495 nm before and after the enzyme reaction.


RESULTS
QP reacted with ALP in the buffer solution of pH=9.5 and incubated for 20 min at 37.0 degrees C were selected as the optimal conditions for the determination of ALP. The linear range and detection limit for the determination of ALP are 1.0-16.0 and 0.229 U/l, respectively. With this method, ALP could be applied to assess ALP in human serum and the results were evaluated by comparison with a standard colorimetric assay using p-nitrophenyl phosphate as ALP substrate.


CONCLUSIONS
This method is simple, practical and can be used as an alternative to assess ALP in clinical analysis.
Zhu
Xiaojing
X
Department of Chemistry, Shandong Normal University, Jinan, 250014, China.
Jiang
Chongqiu
C
D000469:Alkaline Phosphatase / Q000032:analysis* / Q000378:metabolism*; D005470:Fluorometry; D020662:Guanine Nucleotide Exchange Factors; D006801:Humans; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D010755:Organophosphates / Q000737:chemistry / Q000378:metabolism*; D011518:Proto-Oncogene Proteins; D011804:Quinolines / Q000737:chemistry / Q000378:metabolism*; D064067:Rho Guanine Nucleotide Exchange Factors; D013379:Substrate Specificity; D013696:Temperature
C517653:8-quinolyl phosphate; C577228:ARHGEF5 protein, human; D020662:Guanine Nucleotide Exchange Factors; D010755:Organophosphates; D011518:Proto-Oncogene Proteins; D011804:Quinolines; D064067:Rho Guanine Nucleotide Exchange Factors; D000469:Alkaline Phosphatase