Phospholipase D functions well in both hydrolysis and transphosphatidylation
reactions. In the latter, alcohols occurring naturally in glycerophospholipids and
other alcohols can be incorporated. Some of the phospholipase D enzymes have
relatively broad substrate specificity, and the kinetics are often favor the transpho-
sphatidylation reaction. However, it is beyond the scope of this text to describe all the
reactions possible (for a recent review, see Servi, 1999; see also Chapters on Phos-
pholipases).
On occasion, it is beneficial to use a combination of phospholipases C and D. A
glycerophospholipid such as phosphatidylcholine can thus be used to phosphorylate
an alcohol. In the first step, the alcohol to be phosphorylated replaces the choline in
the polar group of the phospholipid by a phospholipase D-catalyzed transphospha-
tidylation (Figure 9). In the next step, phospholipase C cleaves the phosphoester
bond on the other side of the phosphate, producing a diacylglycerol and the phos-
phorylated alcohol (Virto and Adlercreutz, 2000b) (Figure 9).
304 14 Enzymatic Conversions of Glycerophospholipids
Figure 9. Example of the combined use of phospholipases C and D (PLC, PLD) to produce phospho-
rylated compounds, in this case lysophosphatidic acid (LPA). PC, phosphatidylcholine. (From Virto and
Adlercreutz, 2000b.)
Table 3.List of the enzymatic glycerophospholipid conversions
which have been shown to work reasonably well.
Enzyme Reactions
Lipase H, E, T
Phospholipase A 2 H, E
Phospholipase C H
Phospholipase D H, T
H, hydrolysis; E, esterification; T, transesterification.