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Food Lipids: Chemistry, Nutrition, and Biotechnology

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CPT (DAG ↔ PC) Extensive involvement, 4 not<br />

selective<br />

LPCAT (PC ↔ lysoPC)<br />

(or PLA 2)<br />

Extensive involvement;<br />

selective toward 18:1 �9-<br />

CoA for acylation;<br />

selective toward<br />

18:2 �9,12/18:3 �9,12,15 for<br />

deacylation; contributes<br />

18:X to acyl-CoA pool<br />

Acyl-CoA pool Important for GPAT <strong>and</strong><br />

DAGAT steps<br />

Not selective; DAGAT<br />

selectivity leaves di-18:1 �9acylglycerol<br />

for exchange<br />

into PC<br />

Little evidence for involvement Moderate involvement;<br />

controls unsaturation of<br />

18:X at sn-2 site<br />

Less important than enzyme<br />

selectivity features<br />

N/A Extensive involvement<br />

(required for acyl<br />

group oxygenation/<br />

Important for GPAT step<br />

<strong>and</strong> somewhat important<br />

for DAGAT step<br />

modification)<br />

Extensive involvement;<br />

contributes oxygenated<br />

fatty acids to the acyl-<br />

CoA pool<br />

Important especially for<br />

GPAT <strong>and</strong> LPAAT<br />

steps; profile<br />

controlled by LPCAT<br />

(or PLA 2)<br />

Notes (comments or notable exceptions)<br />

1<br />

Cocoa bean enzyme is selective for 16:0/18:0-CoA.<br />

2<br />

Palm kernel enzyme recognizes 12:0-LPA.<br />

3<br />

Cocoa bean/borage enzymes have greater selectivity.<br />

4<br />

Except in cocoa bean <strong>and</strong> avocado.<br />

5<br />

Palm kernel <strong>and</strong> coconut enzymes also form mixed 12:0/18:1�9-PA species as major products.<br />

6<br />

Meadowfoam enzyme is an exception.<br />

7<br />

Inferred from properties of GPAT from plant tissues in general.<br />

8<br />

Inferred from properties of LPAAT from plant tissues in general.<br />

a<br />

Abbreviations for enzymes <strong>and</strong> fatty acids are the same as in Table 5 <strong>and</strong> footnote 1 (Sec. II); respectively. Other abbreviations: PA, phosphatidic acid; LPA,<br />

lysophosphatidic acid; DAG, diacylglycerol; PC, phosphatidylcholine; LPC, lysophosphatidylcholine; PLA2, phospholipase A2, N/A, not appropriate or not available.<br />

Copyright 2002 by Marcel Dekker, Inc. All Rights Reserved.

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