title: A novel enzymatic method for measuring mizoribine 5'-monophosphate levels in serum.
abstract: Inosine 5'-monophosphate dehydrogenases (IMPDH) from Oceanobacillus iheyensis and Bacillus subtilis were biochemically characterized with the aim of establishing a mizoribine 5'-monophosphate (MZR-P) assay. MZR-P is the active metabolite of mizoribine, which has been successfully used as an immunosuppressive agent. A sensitive method for measuring the MZR-P concentration in serum, based on its ability to inhibit IMPDH, was developed. The method was applied to an automatic clinical analyzer, enabling measurement of MZR-P levels in a set of serum samples. MZR-P at concentrations of 0.1-13.6 (microg/ml (0.3-40 microM) in the samples could be measured with 0.7% within-run coefficients of variation.
authors.affiliation: Asahi Kasei Pharma Corporation, 632-1 Mifuku, Izunokuni-shi, Shizuoka, Japan.
authors.forename: Hiroko
authors.initials: H
authors.lastname: Ota
authors.forename: Yuko
authors.initials: Y
authors.lastname: Yasuda
authors.forename: Shin-ichi
authors.initials: S
authors.lastname: Sakasegawa
authors.forename: Shigeyuki
authors.initials: S
authors.lastname: Imamura
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Tamura
mesh_terms: D001331:Automation; D001407:Bacillus / Q000201:enzymology; D001412:Bacillus subtilis / Q000201:enzymology; D001671:Biochemistry / Q000379:methods; D001709:Biotechnology / Q000379:methods; D001774:Blood Chemical Analysis / Q000295:instrumentation / Q000379:methods*; D002412:Cations; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007168:IMP Dehydrogenase / Q000737:chemistry; D007166:Immunosuppressive Agents / Q000494:pharmacology; D011994:Recombinant Proteins / Q000737:chemistry; D012263:Ribonucleosides / Q000032:analysis* / Q000097:blood*
chemical_list: D002412:Cations; D007166:Immunosuppressive Agents; D011994:Recombinant Proteins; D012263:Ribonucleosides; C010052:mizoribine; D007168:IMP Dehydrogenase