Fatty acid synthase (FAS; acyl-CoA:malonyl-CoA C-acyltransferase [decarboxylating, oxoacyl- and enoyl-reducing and thioester-hydrolyzing], EC 220.127.116.11) is an important enzyme participating in energy metabolism in vivo which is related to adiposis and cancer [Cancer Lett. 167 (1) (2001) 99; Nat. Med. 8 (4) (2002) 335]. Tests of fast- and slow-binding inhibitions showed that fatty acid synthase of chicken liver is rapidly and irreversibly inactivated by low Zn2+ concentrations. Electrophoresis and FPLC results showed that FAS cross-links occurred in the presence of high Zn2+ concentrations (>4 μM) which may be another reason that FAS lost its activity. The modification velocity of FAS by DTNB decreased with increasing Zn2+ concentration, which confirmed that Zn2+ interacted with SH groups. Substrate protective experiments and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed that all three substrates tested had some protective effects on FAS in the presence of Zn2+, and malonyl-CoA was the most effective of the three substrates. In the presence of malonyl-CoA, the activity loss of FAS decreased sharply and almost no cross-link was observed in SDS-PAGE. This suggests that the phosphopantetheine SH group is the critical group in the cross-link and inhibition of FAS in the presence of Zn2+.
|Original language||English (US)|
|Number of pages||10|
|Journal||International Journal of Biochemistry and Cell Biology|
|State||Published - Mar 1 2003|
- Fatty acid synthase
ASJC Scopus subject areas
- Cell Biology