SUBSTRATE-SPECIFICITY OF SQUALENE SYNTHETASE

  • 1 January 1980
    • journal article
    • research article
    • Vol. 617  (2) , 218-224
Abstract
Artificial homologues (22) of farnesyl pyrophosphate were examined for the reactivity as substrate for squalene synthetase of pig liver microsomes. Of the homologues, 16 were reactive to give corresponding squalene-like products. Extention of the .omega.-terminal of the C chain of farnesyl pyrophosphate is acceptable to the enzyme at least by 2 C atoms in either trans or cis direction (2E,6E)-3,7,11-Trimethyldodeca-2,6-dienyl- and (2E,6E)-3,7-dimethyldodeca-2,6-dienyl pyrophosphates are both good substrates, whereas (2E,6E)-3,7-dimethylundeca-2,6-dienyl-, (2E,6E)-3,7-dimethyltrideca-2,6-dienyl-, (2E,6E)-3,7-dimethyltetradeca-2,6-dienyl-, (2E,6E)-3,7,10-trimethylundeca-2,6-dienyl- and (2E,6E)-3,7,12-trimethyltrideca-2,6-dienyl pyrophosphates are poor substrates. The C chain length rather than 10,11-double bond is important for the reactivity as substrate. Replacement of 3-methyl of farnesyl pyrophosphate by an ethyl group or introduction of a methyl group at C-4 results in complete loss of activity.

This publication has 1 reference indexed in Scilit: