Publications

• Enzymatic characterization of class I DAD1-like acylhydrolase members targeted to chloroplast in Arabidopsis.

  Seo Y.S., Kim E.Y., Kim J.H., Kim W.T.

  In Arabidopsis, there are at least seven class I acylhydrolase members, which have a putative N-terminal chloroplast-targeting signal. Here, we show that all seven class I proteins are localized to the chloroplasts and hydrolyze phosphatidylcholine at the sn-1 position. However, based on their act ... >> More

  In Arabidopsis, there are at least seven class I acylhydrolase members, which have a putative N-terminal chloroplast-targeting signal. Here, we show that all seven class I proteins are localized to the chloroplasts and hydrolyze phosphatidylcholine at the sn-1 position. However, based on their activities toward various lipids, Arabidopsis class I enzymes could be further divided into three sub-groups by substrate specificity, one with phospholipase-specific activity, another with phospholipase and galactolipase activities, and the other with broad lipolytic activity toward phosphatidylcholine, galactolipids, and triacylglycerol. These results suggest that the three sub-groups of class I acylhydrolases have specific roles in chloroplasts. << Less

  FEBS Lett. 583:2301-2307(2009) [PubMed] [EuropePMC]

  This publication is cited by 2 other entries.

• Further biochemical characterization of human pancreatic lipase-related protein 2 expressed in yeast cells.

  Eydoux C., De Caro J., Ferrato F., Boullanger P., Lafont D., Laugier R., Carriere F., De Caro A.

  Recombinant human pancreatic lipase-related protein 2 (rHPLRP2) was produced in the protease A-deficient yeast Pichia pastoris. A major protein with a molecular mass of 50 kDa was purified from the culture medium using SP-Sepharose and Mono Q chromatography. The protein was found to be highly sens ... >> More

  Recombinant human pancreatic lipase-related protein 2 (rHPLRP2) was produced in the protease A-deficient yeast Pichia pastoris. A major protein with a molecular mass of 50 kDa was purified from the culture medium using SP-Sepharose and Mono Q chromatography. The protein was found to be highly sensitive to the proteolytic cleavage of a peptide bond in the lid domain. The proteolytic cleavage process occurring in the lid affected both the lipase and phospholipase activities of rHPLRP2. The substrate specificity of the nonproteolyzed rHPLRP2 was investigated using pH-stat and monomolecular film techniques and various substrates (glycerides, phospholipids, and galactolipids). All of the enzyme activities were maximum at alkaline pH values and decreased in the pH 5-7 range corresponding to the physiological conditions occurring in the duodenum. rHPLRP2 was found to act preferentially on substrates forming small aggregates in solution (monoglycerides, egg phosphatidylcholine, and galactolipids) rather than on emulsified substrates such as triolein and diolein. The activity of rHPLRP2 on monogalactosyldiglyceride and digalactosyldiglyceride monomolecular films was determined and compared with that of guinea pig pancreatic lipase-related protein 2, which shows a large deletion in the lid domain. The presence of a full-length lid domain in rHPLRP2 makes it possible for enzyme activity to occur at higher surface pressures. The finding that the inhibition of nonproteolyzed rHPLRP2 by tetrahydrolipstatin and diethyl-p-nitrophenyl phosphate does not involve any bile salt requirements suggests that the rHPLRP2 lid adopts an open conformation in aqueous media. << Less

  J. Lipid Res. 48:1539-1549(2007) [PubMed] [EuropePMC]

  This publication is cited by 8 other entries.

• The beta5-Loop and Lid Domain Contribute to the Substrate Specificity of Pancreatic Lipase-related Protein 2 (PNLIPRP2).

  Xiao X., Lowe M.E.

  Pancreatic triglyceride lipase (PNLIP) is essential for dietary fat digestion in children and adults, whereas a homolog, pancreatic lipase-related protein 2 (PNLIPRP2), is critical in newborns. The two lipases are structurally similar, yet they have different substrate specificities. PNLIP only cl ... >> More

  Pancreatic triglyceride lipase (PNLIP) is essential for dietary fat digestion in children and adults, whereas a homolog, pancreatic lipase-related protein 2 (PNLIPRP2), is critical in newborns. The two lipases are structurally similar, yet they have different substrate specificities. PNLIP only cleaves neutral fats. PNLIPRP2 cleaves neutral and polar fats. To test the hypothesis that the differences in activity between PNLIP and PNLIPRP2 are governed by surface loops around the active site, we created multiple chimeras of both lipases by exchanging the surface loops singly or in combination. The chimeras were expressed, purified, and tested for activity against various substrates. The structural determinants of PNLIPRP2 galactolipase activity were contained in the N-terminal domain. Of the surface loops tested, the lid domain and the β5-loop influenced activity against triglycerides and galactolipids. Any chimera on PNLIP with the PNLIPRP2 lid domain or β5-loop had decreased triglyceride lipase activity similar to that of PNLIPRP2. The corresponding chimeras of PNLIPRP2 did not increase activity against neutral lipids. Galactolipase activity was abolished by the PNLIP β5-loop and decreased by the PNLIP lid domain. The source of the β9-loop had minimal effect on activity. We conclude that the lid domain and β5-loop contribute to substrate specificity but do not completely account for the differing activities of PNLIP and PNLIPRP2. Other regions in the N-terminal domain must contribute to the galactolipase activity of PNLIPRP2 through direct interactions with the substrate or by altering the conformation of the residues surrounding the hydrophilic cavity in PNLIPRP2. << Less

  J. Biol. Chem. 290:28847-28856(2015) [PubMed] [EuropePMC]

  This publication is cited by 3 other entries.