Studies of the phospholipase A2 activity of rat ileal mucosa.
A rapid and simple procedure has been used to determine phospholipase A2 activity (EC 3.1.1.4) in rat ileal mucosa. We used 14C-oleate-labeled Escherichia coli as substrate for the phospholipase activity and a 0.45-micron Millipore filter to separate the product of hydrolysis--the 14C-oleic acid--from the unhydrolyzed substrate. The phospholipase A2 activity was optimal at pH 9.8 and at 2 mM Ca2+, but another peak of activity appeared at pH 7.2. In addition, cell fractionation revealed yet another phospholipase A2 activity at pH 5.0 in the absence of Ca2+. These findings suggest the presence of more than one phospholipase A2 in the ileal mucosa and points to the possible use of a simple procedure for studying their distribution and properties.
D000818:Animals; D002499:Centrifugation, Density Gradient; D004926:Escherichia coli; D005260:Female; D006863:Hydrogen-Ion Concentration; D007082:Ileum / Q000201:enzymology*; D007413:Intestinal Mucosa / Q000201:enzymology*; D010740:Phospholipases / Q000378:metabolism*; D010741:Phospholipases A / Q000302:isolation & purification / Q000378:metabolism*; D054467:Phospholipases A2; D051381:Rats; D011919:Rats, Inbred Strains
D010740:Phospholipases; D010741:Phospholipases A; D054467:Phospholipases A2