Occurrence and possible roles of acetoacetyl‐CoA thiolase and 3‐ketoacyl‐CoA thiolase in peroxisomes of an n‐alkane‐grown yeast, Candida tropicalis

Abstract

Two kinds of 3‐ketoacyl‐CoA thiolases were found in the peroxisomes of Candida tropicalis cells grown on n‐alkanes (C₁₀◀C₁₃). One was a typical acetoacetyl‐CoA thiolase specific only to acetoacetyl‐CoA, while another was 3‐ketoacyl‐CoA thiolase showing high activities on the longer chain substrates. A high level of the latter thiolase activity in alkane‐grown cells was similar to that of other enzymes constituting the fatty acid β‐oxidation system in yeast peroxisomes. These facts suggest that the complete degradation of fatty acids to acetyl‐CoA is carried out in yeast peroxisomes by the cooperative contribution of acetoacetyl‐CoA thiolase and 3‐ketoacyl‐CoA thiolase.