Proteolytic Activity in Commercial Triacylglycerol Hydrolase Preparations

The proteolytic activity of 34 commercial lipase preparations (CLP) was determined using a labeled casein substrate. Only three CLP were free from proteolytic activity. Porcine pancreatic lipases exhibited levels of proteolytic activity comparable to or greater than that of a reference porcine trypsin. Bacterial lipases contained up to 10% of the proteolytic activity of commercial trypsin. Proteolytic activities in lipases from fungal species were present at low levels (<1% of the activity in trypsin). Among preparations of fungal origin, lipases from Aspergillus niger and Mucor javanicus were highest in proteolytic activity; Aspergillus oryzae and Pseudomonas cepacia lipases were lowest. Proteins in CLP were separated by non-denaturing PAGE; between 4 and 17 protein bands in the range h 6.5- S 200 kDa were observed. With the exception of a single pair of Rhizomucor miehei lipases, the distribution of apparent molecular weights (AMW) was unique to each preparation. Bands of caseinolytic activity in...