A more than 20000-fold purification of human serum lipoamidase is described. This was accomplished by (NH4)2SO4 precipitation and chromatography on DEAE-Sepharose, Blue Sepharose CL-6B and phenyl-Sepharose CL-4B, followed by preparative isoelectric focusing (IEF) and finally by gel-permeation chromatography. Co-precipitation and co-chromatography of lipoamidase and biotinidase activities with e...

In this automated procedure for quantifying biotinidase activity in human serum, a manual colorimetric method that measures conversion of the enzyme's artificial substrate N-biotinyl p-aminobenzoate was modified for use with a Technicon AutoAnalyzer II. The intra-run replicate precision (CV) was 2.1% and the day-to-day CV was 4.6% for quality-control sera. Results were linearly related to bioti...