Biomaterial Database

Rapid induction of microsomal delta 12(omega 6)-desaturase activity in chilled Acanthamoeba castellanii. 1993

A L Jones, and D Lloyd, and J L Harwood

Department of Biochemistry, School of Pure and Applied Biology, University of Wales College of Cardiff, U.K.

The activity of microsomal delta 12-desaturase in Acanthamoeba castellanii was increased after growing cultures were chilled from the optimal growth temperature (30 degrees C) to 15 degrees C. This increase was detectable in microsomes isolated from organisms subjected to only 10 min chilling. The mechanism of induction was investigated. The increase in activity on chilling was greatly reduced when protein synthesis was blocked before the temperature shift. Thus the major mechanism for the induction of delta 12-desaturase is increased protein synthesis. delta 12-Desaturase activity was higher when assayed at 20 degrees C than when assayed at 30 degrees C, but these changes were not due to the increased solubility of O2 at 20 degrees C. The major substrate of delta 12-desaturase was found to be 1-acyl-2-oleoyl phosphatidylcholine.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D007930	Leucine	An essential branched-chain amino acid important for hemoglobin formation.	L-Leucine,Leucine, L-Isomer,L-Isomer Leucine,Leucine, L Isomer
D008041	Linoleic Acids	Eighteen-carbon essential fatty acids that contain two double bonds.	Acids, Linoleic
D008861	Microsomes	Artifactual vesicles formed from the endoplasmic reticulum when cells are disrupted. They are isolated by differential centrifugation and are composed of three structural features: rough vesicles, smooth vesicles, and ribosomes. Numerous enzyme activities are associated with the microsomal fraction. (Glick, Glossary of Biochemistry and Molecular Biology, 1990; from Rieger et al., Glossary of Genetics: Classical and Molecular, 5th ed)	Microsome
D009829	Oleic Acids	A group of fatty acids that contain 18 carbon atoms and a double bond at the omega 9 carbon.	Octadecenoic Acids,Acids, Octadecenoic,Acids, Oleic
D003080	Cold Temperature	An absence of warmth or heat or a temperature notably below an accustomed norm.	Cold,Cold Temperatures,Temperature, Cold,Temperatures, Cold
D000048	Acanthamoeba	A genus of free-living soil amoebae that produces no flagellate stage. Its organisms are pathogens for several infections in humans and have been found in the eye, bone, brain, and respiratory tract.	Acanthamoebas
D000214	Acyl Coenzyme A	S-Acyl coenzyme A. Fatty acid coenzyme A derivatives that are involved in the biosynthesis and oxidation of fatty acids as well as in ceramide formation.	Acyl CoA,Fatty Acyl CoA,Long-Chain Acyl CoA,Acyl CoA, Fatty,Acyl CoA, Long-Chain,CoA, Acyl,CoA, Fatty Acyl,CoA, Long-Chain Acyl,Coenzyme A, Acyl,Long Chain Acyl CoA
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D000841	Anisomycin	An antibiotic isolated from various Streptomyces species. It interferes with protein and DNA synthesis by inhibiting peptidyl transferase or the 80S ribosome system.	Flagecidin