Conformational Similarity between the Active Sites of a Sunflower Seedlings Lipase and a Porcine Pancreatic Lipase

A true triacylglycerol lipase was detected in germinating sunflower (Helianthus annuus L.) seedlings
associated to oleosomes. This enzyme that has not yet been identified was partially purified as shown
by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE) (10%): Two protein
bands, of 61 and 66 kDa, were isolated from the active lipase fraction. Polyclonal antibodies (PAbs)
directed against each protein band were produced. Only PAbs against the 61 kDa protein band
(P-61) were able to inhibit the total lipolytic activity of our preparation. Hence, only the 61 kDa protein
carries the sunflower lipase activity. The relationship between a pure porcine pancreatic lipase
and the P-61 purified sunflower lipolytic fraction was investigated, leading to the first evidence of
cross reaction between the porcine pancreatic lipase and the P-61 sunflower lipase fraction.
These results are in agreement with common epitopes to the porcine pancreatic lipase and the
sunflower P-61.