Maize lipase

In subcellular fractionation of the storage tissues of many germinated seeds, the lipase activity Is present either In the soluble fraction or associated with the membranes of the lipid bodies (see reviews, 18,19). In seeds where the lipase Is found In the soluble fractions, the enzymes In vivo will still have to come In contact with the membrane of the lipid bodies during catalysis. In those seeds where the lipase Is associated with the membrane of the lipid bodies, the enzyme may be loosely (e.g., rapeseed, mustard seed) or tightly (e.g., castor bean and maize) associated with the organelles. 

The seed lipases from five plant species were selected because of their differences In the fatty acid composition of the storage trlacylglycerols. Castor bean contains about 80% rlclnolelc acid maize seed possesses about... 

For each lipase, the activity on one particular triacylglycerol was chosen to represent a 100% relative activity. Relative activities of 100 represent 172 (pancreas), 96 (castor bean), 145 (maize), 32 (rapeseed), 28 (mustard), and 143 (elm) nmol/min. 

Both maize and rapeseed lipases were more active on tri-, than on di-or monollnoleln. Castor bean lipase was equally active on tri-, di-, and monollnoleln, as has been reported realier (9). These relative activities are different from those of pancreatic lipase which is more active on tri-than dlllnoleln, and Is Inactive on monollnoleln. 

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