Effect of products of PLA2 catalyzed hydrolysis of DLPC on motion of rising bubbles.
Local velocities of rising bubbles decrease with the increasing concentration in solution of surface-active, water-soluble species. Therefore, it is possible to use this phenomenon to monitor products of enzymatic reactions, which meet such criteria. In this study, hydrolysis of 1,2-dilauroyl-sn-glycero-3-phosphatidylcholine (DLPC) catalyzed by calcium-dependent phospholipase A2 (PLA2) (EC3.1.1.4) from porcine pancreas was used as model reaction. The products of this reaction are lauric acid (LA) and 1-lauroyl-2-hydroxy-sn-glycero-3-phosphatidylcholine (Lyso-PC). DLPC was dispersed in a chloroform/methanol mixture that was spread on a free PLA2 solution surface. Air bubbles were then formed at a capillary orifice and the local velocity of rising bubbles as a function of the distance from the capillary tip was monitored. Local velocity profiles were compared with profiles recorded for solutions of pure enzymatic reaction products and their mixtures. Our experiments showed that the product, which had a dominating effect on bubble motion retardation, was lyso-phosphatidylcholine. This can be explained by differences in the kinetics of lauric acid and lyso-phosphatidylcholine transfer from the spread layer to the solution.
Jerzy Haber Institute of Catalysis and Surface Chemistry, PAS, Niezapominajek 8, 30-239 Krakow, Poland. Electronic address: nckrzan@cyf-kr.edu.pl.
Marcel
M
Krzan
Jerzy Haber Institute of Catalysis and Surface Chemistry, PAS, Niezapominajek 8, 30-239 Krakow, Poland. Electronic address: ncjarek@cyf-kr.edu.pl.
Ewelina
E
Jarek
Jerzy Haber Institute of Catalysis and Surface Chemistry, PAS, Niezapominajek 8, 30-239 Krakow, Poland. Electronic address: ncwarszy@cyf-kr.edu.pl.
Piotr
P
Warszyński
Structure et Réactivité des Systèmes Moléculaires Complexes, BP 239, CNRS/Université de Lorraine, 54506 Vandoeuvre-lès-Nancy Cedex, France. Electronic address: ewa.rogalska@univ-lorraine.fr.
Ewa
E
Rogalska
D000388:Air; D000818:Animals; D002725:Chloroform / Q000737:chemistry; D006868:Hydrolysis; D007700:Kinetics; D007850:Lauric Acids / Q000737:chemistry*; D008244:Lysophosphatidylcholines / Q000737:chemistry*; D000432:Methanol / Q000737:chemistry; D010179:Pancreas / Q000737:chemistry; D010713:Phosphatidylcholines / Q000737:chemistry*; D054467:Phospholipases A2 / Q000737:chemistry* / Q000302:isolation & purification; D012212:Rheology; D012996:Solutions; D013552:Swine
D007850:Lauric Acids; D008244:Lysophosphatidylcholines; D010713:Phosphatidylcholines; D012996:Solutions; C030358:lauric acid; C015153:1,2-dilauroylphosphatidylcholine; D002725:Chloroform; D054467:Phospholipases A2; D000432:Methanol
1,2-Dilauroyl-sn-glycero-3-phosphatidylcholine (DLPC); 1-Lauroyl-2-hydroxy-sn-glycero-3-phosphatidylcholine (Lyso-PC); Lauric acid (LA); Phospholipase A2 (PLA2); Rising bubble; Surface-activity