Open AccessEnzymes used for the determination of HbA 1C
Author(s) -
Hirokawa Kozo,
Nakamura Kazuo,
Kajiyama Naoki
Publication year - 2004
Publication title -
fems microbiology letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.899
H-Index - 151
eISSN - 1574-6968
pISSN - 0378-1097
DOI - 10.1111/j.1574-6968.2004.tb09581.x
Subject(s) - enzyme , protease , biochemistry , peptide , escherichia coli , aspergillus , chemistry , aspergillus oryzae , glucose oxidase , biology , microbiology and biotechnology , gene
To develop an enzymatic measurement of HbA 1C , two key enzymes, i.e., fructosyl peptide oxidase and Aspergillus protease were characterized. Fructosyl peptide oxidase from Eupenicillium terrenum was a flavoenzyme that could catalyze the oxidation of N ‐(1‐deoxyfructosyl)‐Val‐His. The enzyme showed high specificity toward α‐glycated molecules, therefore it seemed suitable for the HbA 1C assay. Since high levels of FPOX expression seemed toxic to host cells, we applied a gene expression system using a bacteriophage vector and achieved high levels of expression in Escherichia coli . Next, we found that Aspergillus protease was able to digest N ‐(1‐deoxyfructosyl)‐hexapeptide, a glycated peptide that was released from the β‐chain of HbA 1C by Glu‐C endoproteinase. We showed that the N ‐(1‐deoxyfructosyl)‐Val‐His released from N ‐(1‐deoxyfructosyl)‐hexapeptide by Aspergillus protease could be assayed enzymatically using fructosyl peptide oxidase, therefore these enzymes could be applied to the enzymatic measurement of HbA 1C .