Biomaterial Database

Effect of some divalent metal cations on phospholipase C from Bacillus cereus. 1981

C Little

Incubation of phospholipase C from Bacillus cereus with certain divalent metal cations caused enzyme inactivation with Cu(II) being particularly effective. The inactivation arose from the reversible exchange of Zn(II) in the enzyme with the metal cations. Both zinc atoms in the enzyme exchanged rapidly with Cu(II) whereas only one exchanged spontaneously with Co(II). With lecithin substrates, CoZn-phospholipase C had a specific activity of 3.6-11.3% of that of ZnZn-phospholipase C, whereas the CoCo-enzyme was less than 1% active relative to the native enzyme. The CoZn-enzyme had the same Km value for dihexanoyllecithin as had the native enzyme, but the Vm value was markedly lower. ZnZn-, CoZn- and CoCo-phospholipase C all had very low activities towards sphingomyelin micelles, although for the CoCo-enzyme, the sphingomyelinase activity was 4-7-fold greater than for the native enzyme.

UI	MeSH Term	Description	Entries
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
D010738	Type C Phospholipases	A subclass of phospholipases that hydrolyze the phosphoester bond found in the third position of GLYCEROPHOSPHOLIPIDS. Although the singular term phospholipase C specifically refers to an enzyme that catalyzes the hydrolysis of PHOSPHATIDYLCHOLINE (EC 3.1.4.3), it is commonly used in the literature to refer to broad variety of enzymes that specifically catalyze the hydrolysis of PHOSPHATIDYLINOSITOLS.	Lecithinase C,Phospholipase C,Phospholipases, Type C,Phospholipases C
D010740	Phospholipases	A class of enzymes that catalyze the hydrolysis of phosphoglycerides or glycerophosphatidates. EC 3.1.-.	Lecithinases,Lecithinase,Phospholipase
D002413	Cations, Divalent	Positively charged atoms, radicals or groups of atoms with a valence of plus 2, which travel to the cathode or negative pole during electrolysis.	Divalent Cations
D001409	Bacillus cereus	A species of rod-shaped bacteria that is a common soil saprophyte. Its spores are widespread and multiplication has been observed chiefly in foods. Contamination may lead to food poisoning.