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Substrate interferes with dimerisation of outer membrane phospholipase A
Author(s) -
Kingma Roelie L,
Egmond Maarten R
Publication year - 2002
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(02)02461-4
Subject(s) - dimer , substrate (aquarium) , biophysics , chemistry , membrane , kinetics , monomer , lag , covalent bond , in vivo , lag time , biochemistry , biology , organic chemistry , ecology , computer network , physics , microbiology and biotechnology , quantum mechanics , computer science , biological system , polymer
Outer membrane phospholipase A (OMPLA) activity is regulated by reversible dimerisation with the dimer being the active species. Observed lag phases in activity indicated that dimerisation may be slow relative to turnover. A covalent OMPLA dimer indeed did not display lag phase behaviour. A model for OMPLA kinetics was proposed accounting for a slow dimerisation step. Preincubation conditions determined the initial amount of monomer and influenced both lag times and final activities. Under the conditions used, substrate concentrations higher than 50 mol% inhibited OMPLA activity and increased lag times. Our results may shed more light on mechanisms controlling OMPLA activity in vivo.