Application of potato lipid acyl hydrolase for the synthesis of monoacylglycerols

Abstract

Protein extracts from potato tubers contain a lipid acyl hydrolase (LAH) with an unusual selectivity. The component responsible for the enzyme activity is a group of closely related glycoproteins, known as patatin. Potato LAH catalyzes the rapid hydrolysis of monoacylglycerols (MAG), but in contrast expresses only low activity with di-and triacylglycerols. The selectivity of the LAH can be exploited for the synthesis of MAG from fatty acids and glycerol in microaqueous reaction systems. Oleic, linoleic, linolenic, capric, lauric, and myristic acids can be used as reactants, and in each case the reaction products contain >95 mol% MAG and <5 mol% diacylglycerol. By removing water from the reaction mixture by distillation under vacuum, excellent conversions of fatty acids into MAG are possible. Low conversions are observed with palmitic and stearic acids, because of the necessity to use a high temperature (70°C) to maintain a liquid reaction mixture. Potato LAH is rapidly inactivated at 70°C in the microaqueous reaction systems. Potato LAH also catalyzes the selective synthesis of monoesters from oleic acid and simple diols. With oleic acid and diglycerol, monoesters are again the main reaction products, but 17 mol% diesters are also formed.

Cloning, expression, purification and characterization of patatin, a novel phospholipase A

“…These results show that chain length preference as noted above (maximum for C 10 ) is not absolute, as activity increases with chain length for the series of mono-acyl-glycolphosphocholines from C 12 to C 16 . The highest specific activities were obtained with the synthetic phospholipids diC 8 PCho and diC 9 PCho.…”

“…Recently, patatin was found to be identical to a cytosolic Abbreviations: DTNB, 5,5'-dithio-bis(2-nitrobenzoic acid); cPLA 2 , cytosolic calcium-dependent phospholipase A 2 ; PatB2, Patatin subclass B2. Definition: phospholipids are named according to the IUBMB recommmendations as follows: PCho, phosphocholine; diC 6 PCho, 1,2-dihexanoyl-sn-glycero-3-phosphocholine; diC 7 PCho, 1,2-diheptanoyl-sn-glycero-3-phosphocholine; diC 8 PCho, 1,2-dioctanoyl-sn-glycero-3-phosphocholine; diC 9 PCho, 1,2-dinonanoyl-sn-glycero-3-phosphocholine; diC 10 PCho, 1,2-didecanoyl-sn-glycero-3-phosphocholine; diC 12 PCho, 1,2-didodecanoyl-sn-glycero-3-phosphocholine; diC 16 PCho, 1,2-dihexadecanoyl-sn-glycero-3-phosphocholine; C 18 lysoPCho, 1-octadecanoyl-2-lyso-sn-glycero-3-phosphocholine; C 8 thioglycolPCho, 2-octanoylthio-ethane-1-phosphocholine; C 12 thioglycolPCho, 2-dodecanoylthio-ethane-1-phosphocholine; C 16 thioglycolPCho, 2-hexadecanoylthio-ethane-1-phosphocholine; diC 8 dithioPCho, rac-1,2-dioctanoyldithiopropyl-3-phosphocholine phospholipase A 2 (cPLA 2 ) from potato [15], shedding new light on its possible physiological function. As a storage protein, patatin is mainly localized in the vacuoles where it is inactive.…”

Influence of Drought and Wounding Stress on Soluble Phenols and Proteins in Potato Tubers

“…Moreover, the effects of drought stress on the level of free amino acids (AAS) and the activity of lipid acyl hydrolases (LAH) associated with the glycoprotein patatin comprising about 30% of the soluble proteins in potato tubers (Moreau & Nagahashi, 1987) was investigated. LAH present in protein extracts from potato tubers are lipolytic enzymes with different substrate preference (Anderson et al, 2002;Andrews et al, 1988;Hasson & Laties, 1976) that are capable of hydrolysing monoacylglycerols (MAG), phospholipids and galactolipids to form fatty acids and fatty acid hydroperoxides (Galliard, 1971), but can also be used under certain conditions to synthesize MAG (Macrae et al, 1998). Changes in the composition of membrane lipids may contribute to protect cell membranes under stress conditions (Gigon et al, 2004).…”

Patatin, the major protein of potato (Solanum tuberosum L.) tubers, and its occurrence as genotype effect: processing versus table potatoes

“…The processing genotypes are characterised by a longer growing season, and high a starch concentration; the tuber protein was considered to be an unwanted by-product of the starch production rather than a valuable raw material for further processing. However, because of the above mentioned nutritional and biochemical potential of potato tuber proteins and especially patatin (Strickland et al 1995;Macrae et al 1998;Ralet & Guéguen 2000;Tonón et al 2001;Åhman & Melander 2003;Wang & Xiong 2005), efforts exist to isolate tuber proteins from potato fruit water for utilisation in feed, food, and biotechnological applications (Straetkvern et al 1999;Koningsveld et al 2001). Information describing the genotype and annual stability of patatin presence in potato tubers as well as correlations between patatin abundance and the selected characteristics (tubers size, pure protein content, starch content), is basic for the production and future utilisation of this protein component in various branches.…”