Not available outside of the UK & Ireland.

Analysis Note

Protein determined by biuret.

Application

This enzyme is useful for enzymatic determination of creatinine when coupled with creatine amidinohydrolase, sarcosine dehydrogenase or sarcosine oxidase and formaldehyde dehydrogenase in clinical analysis.

Creatininase from microorganisms may be used in the preparation of amperometric biosensor by co-immobilization with other enzymes for the determination of creatinine.

Biochem/physiol Actions

Creatininase from Pseudomonas sp. is a homohexameric enzyme with a molecular mass of 28.4 kDa per subunit. It is a cyclic amidohydrolase catalysing the reversible conversion of creatinine to creatine. Each monomer contains a binuclear zinc centre near the C termini of the β-strands and the N termini of the main α-helices. These zinc ions indicate the location of the active site.

Packaging

1000 units in glass bottle

Physical form

Lyophilized powder containing sucrose and BSA as stabilizers

Physical properties

Isoelectric point: 4.7Michaelis constants: 3.2 x 10‾²M (Creatinine), 5.7 x 10‾²M (Creatine)Structure: 6 subunits per mol of enzyme (One mol of zinc is bound to each subunit)Inhibitors: Ag⁺, Hg⁺⁺, N-bromosuccinimide, EDTAOptimum pH: 6.5 − 7.5Optimum temp: 70°CpH Stability: pH 7.5 − 9.0 (5°C, 16hr)Thermal stability: Below 70°C (pH 7.5, 30 min)

Unit Definition

One unit will hydrolyze 1.0 mmole of creatinine to creatine per min at pH 8.0 and 25 °C