tailieunhanh - Báo cáo khoa học: Transphosphatidylation activity of Streptomyces chromofuscus phospholipase D in biomimetic membranes

The phospholipase D (PLD) fromStreptomyces chromo-fuscusbelongs to the superfamily of PLDs. All the enzymes included in this superfamily are able to catalyze both hydrolysis and transphosphatidylation activities. However, S. chromofuscusPLD is calcium dependent and is often described as an enzyme with weak transphosphatidylation activity. S. chromofuscus PLD-catalyzed hydrolysis of phospholipids in aqueous medium leads to the formation of phosphatidic acid. | Eur. J. Biochem. 270 4523-4530 2003 FEBS 2003 doi Transphosphatidylation activity of Streptomyces chromofuscus phospholipase D in biomimetic membranes Karim El Kirat1 Annie-France Priaent2 Jean-Paul Chauvet3 Bernard Roux1 and Francoise Besson1 1Laboratoire de Physico-Chimie Biologique UMR CNRS 5013 Villeurbanne Lyon France 2Laboratoire de Biochimie et Pharmacologie UMR INSERM 585 Villeurbanne Lyon France 3Laboratoire d lngenierie et de Fonctionnalization des Surfaces UMR CNRS 5621 Ecully Lyon France The phospholipase D PLD from Streptomyces chromo-fuscus belongs to the superfamily of PLDs. All the enzymes included in this superfamily are able to catalyze both hydrolysis and transphosphatidylation activities. However S. chromofuscus PLD is calcium dependent and is often described as an enzyme with weak transphosphatidylation activity. S. chromofuscus PLD-catalyzed hydrolysis of phospholipids in aqueous medium leads to the formation of phosphatidic acid. Previous studies have shown that phos-phatidic acid-calcium complexes are activators for the hydrolysis activity of this bacterial PLD. In this work we investigated the influence of diacylglycerols naturally occurring alcohols as candidates for the transphosphati-dylation reaction. Our results indicate that the transphos-phatidylation reaction may occur using diacylglycerols as a substrate and that the phosphatidylalcohol produced can be directly hydrolyzed by PLD. We also focused on the surface pressure dependency of PLD-catalyzed hydrolysis of phospholipids. These experiments provided new information about PLD activity at a water-lipid interface. Our findings showed that classical phospholipid hydrolysis is influenced by surface pressure. In contrast phosphatidylalcohol hydrolysis was found to be independent of surface pressure. This latter result was thought to be related to headgroup hydrophobicity. This work also highlights the physiological significance of phosphatidylalcohol .