A sensitive trimethylamine‐N‐oxide aldolase assay in two steps without deproteinisation

Abstract

A two-step assay for trimethylamine-N-oxide aldolase (the target enzyme) is described in which the second step, the indicator reaction, is of the enzymatic end-point type. This indicator reaction is carried out at a slightly alkaline pH, outside the target enzyme's active pH range. An effective inactivation of the target enzyme is thus obtained solely by shifting the pH to that of the indicator reaction, thereby avoiding a deproteinisation step. By inserting a downward pH step as the stopping method, many samples may be collected and applied to the indicator reaction simultaneously. These features make the method very productive and easy to perform.

Quantitative Relationship between Trimethylamine Oxide Aldolase Activity and Formaldehyde Accumulation in White Muscle from Gadiform Fish during Frozen Storage

“…In vitro TMAOase activity was measured according to "procedure A" in Nielsen et al (31). Samples were homogenized (UltraTurax, 20000 rpm) in 5 volumes of 50 mM acetate, 1 M NaCl, pH 4.5.…”