Cross reaction between P-61 sunflower seedlings oleosomal protein band and porcine pancreatic lipase

Abstract

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, P-61 and P-66 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 sunflower P-61 were able to inhibit the total lipolytic activity of our preparation. Hence, only the P-61 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. Key words: Triacylglycerol lipase, oleosomes, polyclonal antibodies, cross-reactivity, Helianthus annuus L.