Characterization of the bacterial enzyme thromboplastinase

The action of phospholipase C on ethanolamine plasmalogen (2-acyl-1-alkenylglycerylphosphorylethanolamine)

1. The phospholipase C of Bacillus cereus attacks the ethanolamine plasmalogen of brain to yield a plasmalogenic diglyceride (2-acyl-1-alkenylglycerol). 2. This plasmalogenic diglyceride is analogous to the material obtained by the action of the phospholipase C of Clostridium welchii on the choline plasmalogen of heart.

Characterization of the Phospholipases of Bacillus cereus and Their Effects on Erythrocytes, Bone, and Kidney Cells

Slein, Milton W. (Fort Detrick, Frederick, Md.), and Gerald F. Logan, Jr. Characterization of the phospholipases of Bacillus cereus and their effects on erythrocytes, bone, and kidney cells. J. Bacteriol. 90:69-81. 1965.-Culture filtrates of Bacillus cereus contain phospholipases that split phosphoryl choline, phosphoryl ethanolamine, and phosphoryl inositol from the phospholipids phosphatidyl choline (PTC), sphingomyelin, phosphatidyl ethanolamine (PTE), and phosphatidyl inositol (PTI). It is possible that one enzyme catalyzes the degradation of PTE and PTC, but the other phospholipases appear to be separate entities. Some activity on phosphatidyl serine has also been noted. Quantitative paper chromatography has been used for characterizing the phospholipases that are separated on N,N'-diethylaminoethyl cellulose columns. A procedure for the analysis of inositol is included. A sensitive kidney cortex homogenate test is described that depends on the release of alkaline phosphatase for the measurement of phosphatasemia factor (PF) activity associated with the phospholipases. The effects of the phospholipases on erythrocytes, kidney, and bone cells are discussed. Hemolysin activity is inhibited by crude soybean "lecithin," but hemolysis does not seem to be identical with PTE- or PTC-phospholipase activity. PF activity is also inhibited by the "lecithin." Highest PF activity is associated with PTI-phospholipase. The phospholipase fractions differ in their sensitivities to trypsin. Phospholipases with similar properties have been obtained from culture filtrates of B. anthracis.

The catabolism of phosphatidylethanolamine by the rumen protozoon Entodinium caudatum and its conversion into the N-(1-carboxyethyl) derivative

1. The N-(2-hydroxyethyl)alanine esterified to phosphatidic acid in anaerobic ciliate rumen protozoa has the l configuration. 2. Labelling experiments with Entodinium caudatum cultures using [(32)P]P(i) [2-(14)C]ethanolamine and (32)P- and (14)C-labelled phosphatidylethanolamine show that phosphatidylethanolamine is the direct lipid precursor of the N-(2-hydroxyethyl)alanine-containing phospholipid. 3. Labelling experiments with [(14)C]starch, [(14)C]lactate and [(14)C]pyruvate with E. caudatum cultures indicate that a three-carbon glycolytic intermediate is probably the precursor of the N-(1-carboxyethyl) grouping which substitutes on the amino group of phosphatidylethanolamine. 4. [(32)P]phosphatidylethanolamine is catabolized by E. caudatum forming initially glycerylphosphorylethanolamine and subsequently glycerophosphate and P(i). A little phosphorylethanolamine formed may possibly arise from bacterial enzymes ingested by the protozoa.

THE ACTION OF CLOSTRIDIUM PERFRINGENS PHOSPHATIDASE ON THE LIPOVITELLINS AND OTHER EGG YOLK CONSTITUENTS

A study was made of the action of phosphatidase D (phospholipase D) from Clostridium perfringens (C. welchii) on five constituents of the yolk of hens' eggs (α- and β-lipovitellin, the low-density lipoprotein fraction, granules, and lecithin) in aqueous solution, in the absence and presence of chloroform. Although the untreated lipovitellins were little affected by the enzyme, after absorption of chloroform, a large proportion of their phospholipids was hydrolyzed. In this respect they resembled lecithin but differed from the low-density yolk lipoproteins, whose phospholipids were rapidly hydrolyzed by the enzyme in the presence or absence of chloroform. The mechanism of this type of chloroform activation is discussed.

THE ACTION OF CLOSTRIDIUM PERFRINGENS PHOSPHATIDASE ON THE LIPOVITELLINS AND OTHER EGG YOLK CONSTITUENTS

A study was made of the action of phosphatidase D (phospholipase D) from Clostridium perfringens (C. welchii) on five constituents of the yolk of hens' eggs (α- and β-lipovitellin, the low-density lipoprotein fraction, granules, and lecithin) in aqueous solution, in the absence and presence of chloroform. Although the untreated lipovitellins were little affected by the enzyme, after absorption of chloroform, a large proportion of their phospholipids was hydrolyzed. In this respect they resembled lecithin but differed from the low-density yolk lipoproteins, whose phospholipids were rapidly hydrolyzed by the enzyme in the presence or absence of chloroform. The mechanism of this type of chloroform activation is discussed.