Modified sarcosine oxidases, modified sarcosine oxidase genes, and methods for preparing the modified sarcosine oxidases

Abstract

A modified sarcosine oxidase having a lowered activity for N-ethylglycine. Such a modified oxidase may have the following physicochemical properties: (a) action: hydrolyzes 1 mol of sarcosine to produce 1 mol of glycine and 1 mol of formaldehyde; (b) substrate specificity: reactivity for N-ethylglycine is 70% or less compared with that of an unmodified protein; (c) optimal pH: around 8.0; (d) stable pH range: between 6.5 and 11.0; (e) optimal temperature: 55° C.; (f) thermostability: 55° C. or less; and (g) molecular weight: approximately 43,000 (SDS-PAGE). Genes, vectors and host cells encoding or expressing modified sarcosine oxidases. The modified sarcosine oxidases of the present invention can be used as reagents for measuring creatinine or creatine. The reagents containing the modified sarcosine oxidases used therein are hardly affected by N-ethylglycine, enabling more precise measurement than ever before.

Dependencies are inferred from the claim text.