Specific release of the thioesterase component of the fatty acid synthetase multienzyme complex by limited trypsinization.

AUTOR(ES)

Smith, S

RESUMO

Limited trypsinization of the fatty acid synthetase multienzyme complex from rat mammary gland results in the release of a protein, molecular weight 32,000, with thioesterase activity. The other components of the multienzyme complex--the acyl carrier protein, acetyl and malonyl transferases, condensing enzyme, keto reductase, dehydrase and enoyl reductase--are not affected and remain associated with the complex. The thioesterase can be isolated by ammonium sulfate precipitation and gel filtration. Extensive trypsinization of fatty acid synthetase multienzyme complex results in a loss of thioesterase activity, probably due to cleavage of the thioesterase component into inactive peptides. However, the molecular weight and specific activity of the thioesterase isolated after limited trypsinization is relatively unaffected by the severity of the conditions of proteolysis. Both the thioesterase and the residual trypsinized complex react with antibodies produced against the native multienzyme. The results demonstrate that mild trypsinization can be used to release the thioesterase component of the multienzyme with little perturbation of either the thioesterase or the other components of the complex.

Documentos Relacionados

• CRYSTALLIZATION OF A MULTIENZYME COMPLEX: FATTY ACID SYNTHETASE FROM YEAST
• Fatty acid synthetase from Brevibacterium ammoniagenes: formation of monounsaturated fatty acids by a multienzyme complex.
• Isolation of a multi-enzyme complex of fatty acid oxidation from Escherichia coli.
• Inhibition of fatty acid synthesis in Escherichia coli in the absence of phospholipid synthesis and release of inhibition by thioesterase action.
• Structural basis for channelling mechanism of a fatty acid β-oxidation multienzyme complex