09.12.2012 Views

Food Lipids: Chemistry, Nutrition, and Biotechnology

Food Lipids: Chemistry, Nutrition, and Biotechnology

Food Lipids: Chemistry, Nutrition, and Biotechnology

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

1. Fatty Acid Activation<br />

Prior to degradation by �-oxidation, fatty acids must be converted to an active intermediate,<br />

acyl CoA. In higher plant peroxisomes, fatty acids can be activated by<br />

two mechanisms.<br />

Straight chain fatty acids are usually activated by an acyl-CoA ligase (EC<br />

6.2.1.3). Acyl-CoA ligase is a membrane-bound enzyme <strong>and</strong> is located inside plant<br />

peroxisomes [15]. As in mammalian tissues, common addition of ATP, Mg 2� , <strong>and</strong><br />

CoA-SH to broken peroxisomes as the enzyme source results in the formation of<br />

acyl CoA, AMP, <strong>and</strong> pyrophosphate in a 1:1:1 stoichiometry [9,15].<br />

The activation of straight chain fatty acids by acyl-CoA ligase is dependent on<br />

chain length [9,15,16]. Optimum activity of the enzymes has mainly been observed<br />

with C12, C14, orC16 saturated fatty acids or C18 unsaturated fatty acids. Short chain<br />

fatty acids (including propionic acid) are rather poor substrates (reaction rates

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!