Biomaterial Database

alpha-Isopropylmalate synthase from yeast. A zinc metalloenzyme. 1980

P R Roeder, and G B Kohlhaw

Highly purified alpha-isopropylmalate synthase (3-hydroxy-4-methyl-3-carboxyvalerate 2-oxo-3-methylbutyrate-lysase (coA-acetylating), EC 4.1.3.12) from Saccharomyces cerevisiae is inactivated by various chelating agents. Atomic absorption spectrometry indicates that the enzyme contains approx. four gatoms of zinc per dimer of molecular weight of 130 000. Dialysis against ethylenediaminetetraacetic acid at an initial concentration of 0.1 mM reduces the zinc content to about two gatoms of zinc per dimer. While such enzyme remains active, it has altered kinetic properties and is stimulated by Mn2+, in contrast to untreated enzyme. Dialysis against ethylenediaminetetraacetic acid at an initial concentration of 50 mM reduces the zinc content by more than 80% and causes almost complete loss of enzymatic activity. Activity can be restored by the addition of Zn2+, Mn2+, Fe2+, Co2+, or Cd2+.

UI	MeSH Term	Description	Entries
D007652	Oxo-Acid-Lyases	Enzymes that catalyze the cleavage of a carbon-carbon bond of a 3-hydroxy acid. (Dorland, 28th ed) EC 4.1.3.	Ketoacid-Lyases,Ketoacid Lyases,Oxo Acid Lyases
D008667	Metalloproteins	Proteins that have one or more tightly bound metal ions forming part of their structure. (Dorland, 28th ed)	Metalloprotein
D008670	Metals	Electropositive chemical elements characterized by ductility, malleability, luster, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. (Grant & Hackh's Chemical Dictionary, 5th ed)	Metal
D002614	Chelating Agents	Chemicals that bind to and remove ions from solutions. Many chelating agents function through the formation of COORDINATION COMPLEXES with METALS.	Chelating Agent,Chelator,Complexons,Metal Antagonists,Chelators,Metal Chelating Agents,Agent, Chelating,Agents, Chelating,Agents, Metal Chelating,Antagonists, Metal,Chelating Agents, Metal
D012441	Saccharomyces cerevisiae	A species of the genus SACCHAROMYCES, family Saccharomycetaceae, order Saccharomycetales, known as "baker's" or "brewer's" yeast. The dried form is used as a dietary supplement.	Baker's Yeast,Brewer's Yeast,Candida robusta,S. cerevisiae,Saccharomyces capensis,Saccharomyces italicus,Saccharomyces oviformis,Saccharomyces uvarum var. melibiosus,Yeast, Baker's,Yeast, Brewer's,Baker Yeast,S cerevisiae,Baker's Yeasts,Yeast, Baker
D015032	Zinc	A metallic element of atomic number 30 and atomic weight 65.38. It is a necessary trace element in the diet, forming an essential part of many enzymes, and playing an important role in protein synthesis and in cell division. Zinc deficiency is associated with ANEMIA, short stature, HYPOGONADISM, impaired WOUND HEALING, and geophagia. It is known by the symbol Zn.
D015079	2-Isopropylmalate Synthase	An enzyme that catalyzes the first step in the biosynthetic pathway to LEUCINE, forming isopropyl malate from acetyl-CoA and alpha-ketoisovaleric acid. This enzyme was formerly listed as EC 4.1.3.12.	alpha-Isopropylmalate Synthase,2 Isopropylmalate Synthase,Synthase, 2-Isopropylmalate,Synthase, alpha-Isopropylmalate,alpha Isopropylmalate Synthase