Galactolipid lipase

Anderson MM, McCarty RE, Zimmer EA. Partial purification of a bean galactolipid lipase and its action on sub-chloroplast particles. Plant Physiol 1974 53 699-704. 

Fatty acids do not exist normally in the free state. Fats and oils are predominantly triesters of fatty acids and glycerol, commonly called triglycerides . These fatty acids may be saturated, mono-unsaturated or polyunsaturated. In addition to triglycerides, oils and fats also contain monoglycerides, diglycerides, phospholipids, galactolipids, free fatty acids emerging due to the action of lipases, and small amounts of substances such as sterols, terpenes, tocopherols and other fat soluble vitamins. 

Galactolipids were isolated by preparative tic and were hydrolysed using Rhizopus lipase. Released fatty acids and fatty acids from the lyso-lipids were separated by a combination of argentation and reverse-phase tic. 

In our studies, the analysis of galactolipid hydrolysis kinetics of the thylakoid membrane in the presence of the lipase from Rhizopus arrhizus is the basis for the determination of galactolipid transmembrane distribution. These kinetics have been studied under a variety of conditions temperature, ionic strength, surface potential, stacked or unstacked thylakoids. 

Phospholipase (PLA ) from Vipera russelli and lipase from Rhizopus arrhizus (LRa) were used to obtain almost complete phospholipid (PL) and galactolipid (GL) depletion in the outer monolayer of thylakoid membranes from atrazine-suscepti-ble (S) and -resistant (R) biotypes of Solarium nigrum, PL- and GL-depletion inhibited uncoupled H20/ferricyanide (FeCy) electron flow by 7 and 27%, respectively (not shown). Binding and inhibitory properties of DCMU and atrazine were then studied (Table I). 

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