Differential hydrolysis of immobilized phosphatidylcholines by phospholipases A2 and C.
A novel phospholipid, 1-fatty acyl-2-(12-aminododecyl) phosphatidylcholine (APC), was synthesized and reacted with two different activated agarose matrices, differing in the spacer arm length: N-hydroxysuccinimidylester agarose (1-atom spacer arm) and N-hydroxysuccinimidylester-6-aminohexanoic acid agarose (8-atom spacer arm). Both immobilized phosphatidylcholines were readily degraded by Bacillus cereus phospholipase C at similar rates. By contrast, Crotalus adamanteus phospholipase A2 hydrolyzed long-spacer arm phosphatidylcholine, but had less than one tenth of the activity towards the short-spacer arm one. These results are interpreted in terms of a chain length-related steric hindrance caused by the matrix, affecting phospholipase A2 but not phospholipase C activity, supporting the view that the first involves a deeper burrowing of the substrate into the enzyme molecule.
Delfino
J M
JM
IQUIFIB, Instituto de Química y Fisicoquímica Biológicas, Buenos Aires, Argentina.
Florín-Christensen
J
J
Florín-Christensen
M
M
Richards
F M
FM
D000818:Animals; D001409:Bacillus cereus / Q000201:enzymology; D003435:Crotalid Venoms / Q000201:enzymology; D017839:Crotalus; D006868:Hydrolysis; D010713:Phosphatidylcholines / Q000378:metabolism*; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D013379:Substrate Specificity; D010738:Type C Phospholipases / Q000378:metabolism*
D003435:Crotalid Venoms; D010713:Phosphatidylcholines; D010741:Phospholipases A; D054467:Phospholipases A2; D010738:Type C Phospholipases