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Investigation of phospholipase‐lipid interactions by optical detection of triplet state magnetic resonance spectroscopy
Author(s) -
Mao Su-Yau,
Maki August H.,
de Haas Gerard H.
Publication year - 1985
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 - 10.1016/0014-5793(85)80743-2
Subject(s) - micelle , chemistry , titration , spectroscopy , phosphocholine , nuclear magnetic resonance spectroscopy , nuclear magnetic resonance , residue (chemistry) , crystallography , phospholipid , stereochemistry , biochemistry , membrane , phosphatidylcholine , aqueous solution , physics , quantum mechanics
We have investigated the binding of porcine pancreatic phospholipase A 2 (PA 2 ) to n ‐hexadecylphosphocholine (C 16 PN) micelles using optical detection of triplet state magnetic resonance (ODMR) spectroscopy. The zero field splittings (zfs) of the single Trp 3 residue undergo significant changes upon binding of PA 2 to C 16 PN micelles. Zfs titrations of PA 2 vs C 16 PN indicate that the binding stoichiometry is C 16 PN:PA 2 ~ 25. A reduction of the ¦ E ¦parameter from 1.227 to 1.135 GHz is postulated to result from Stark effects caused by the binding of a polar group (possibly phosphocholine) near Trp 3 in the PA 2 ‐C 16 PN micelle complex.