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Abdelkafi S.,Aix - Marseille University | Abdelkafi S.,University of Sfax | Abousalham A.,University Claude Bernard Lyon 1 | Fendri I.,University of Sfax | And 6 more authors.
Gene | Year: 2012

Phospholipase D (PLD) is a lipolytic enzyme involved in signal transduction, vesicle trafficking and membrane metabolism. It catalyzes the hydrolysis and transphosphatidylation of glycerophospholipids at the terminal phosphodiester bond. The presence of a PLD in the latex of Carica papaya (CpPLD1) was demonstrated by transphosphatidylation of phosphatidylcholine (PtdCho) in the presence of 2% ethanol. Although the protein could not be purified to homogeneity due to its presence in high molecular mass aggregates, a protein band was separated by SDS-PAGE after SDS/chloroform-methanol/TCA-acetone extraction of the latex insoluble fraction. This material was digested with trypsin and the amino acid sequences of the tryptic peptides were determined by micro-LC/ESI/MS/MS. These sequences were used to identify a partial cDNA (723. bp) from expressed sequence tags (ESTs) of C. papaya. Based upon EST sequences, a full-length gene was identified in the genome of C. papaya, with an open reading frame of 2424. bp encoding a protein of 808 amino acid residues, with a theoretical molecular mass of 92.05. kDa. From sequence analysis, CpPLD1 was identified as a PLD belonging to the plant phosphatidylcholine phosphatidohydrolase family. © 2012 Elsevier B.V.

Abdelkafi S.,Aix - Marseille University | Barouh N.,CIRAD - Agricultural Research for Development | Fouquet B.,Biohainaut | Fendri I.,Aix - Marseille University | And 4 more authors.
Plant Foods for Human Nutrition | Year: 2011

Triacylglycerol (TAG) lipases have been thoroughly characterized in mammals and microorganisms, whereas very little is known about plant TAG lipases. The lipolytic activity occurring in all the laticies is known to be associated with sedimentable particles, and all attempts to solubilize the lipolytic activity of Carica papaya latex have been unsuccessful so far. However, some of the biochemical properties of the lipase from Carica papaya latex (CPL) were determined from the insoluble fraction of the latex. The activity was optimum at a temperature of 37°C and a pH of 9. 0, and the specific activities of CPL were found to be 2,000 ± 185 and 256 ± 8 U/g when tributyrin and olive oil were used as substrates, respectively. CPL was found to be active in the absence of any detergent, whereas many lipases require detergent to prevent the occurrence of interfacial denaturation. CPL was inactive in the presence of micellar concentrations of Triton X-100, sodium dodecyl sulfate (SDS) and tetradecyl trimethylammonium bromide (TTAB), and still showed high levels of activity in the presence of sodium taurodeoxycholate (NaTDC) and the zwitterionic Chaps detergent. The effects of various proteases on the lipolytic activity of CPL were studied, and CPL was found to be resistant to treatment with various enzymes, except in the presence of trypsin. All these properties suggest that CPL may be a good candidate for various biotechnological applications. © 2011 Springer Science+Business Media, LLC.

Barouh N.,CIRAD - Agricultural Research for Development | Abdelkafi S.,Aix - Marseille University | Fouquet B.,Biohainaut | Pina M.,CIRAD - Agricultural Research for Development | And 3 more authors.
JAOCS, Journal of the American Oil Chemists' Society | Year: 2010

The non-water-soluble fraction of Carica papaya latex (CPL) constitutes a waste material from papain production; very little information exists regarding its chemical composition. The non-water-soluble fraction of CPL was fractionated by liquid chromatography into neutral lipids, glycolipids and phospholipids. The most abundant compounds were found to be the polar lipids, accounting for 79.2% (w/w) of the total extractible matter, while the total amount of neutral lipids was only around 20%. It was composed of free fatty acids, sterols and triterpenic alcohols, but no glycerides were detected. A high content of saturated fatty acids was measured; these saturated fatty acids were represented by very long chains with C24:0, C26:0 and C28:0 accounting for 6.3, 11.0 and 6.3%, respectively, in the total extractible matter and 7.3, 9.0 and 3.9% in the FFA fraction. The monounsaturated fatty acids were about 23-25% in both samples, with oleic acid (C18:1) being the most abundant. The polyunsaturated fatty acids that were 25.1% in the total matter and 21.6% in the FFA fraction were mainly represented by linoleic acid (C18:2n-6). Finally, a very interesting characteristic of the FA composition of this latex concerns the presence of odd-numbered fatty acids in significant amounts (around 22% in the total extract and 24.3% in the FFA fraction). © 2010 AOCS.

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