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Modification of Tyrosine‐3 (63) and Lysine‐6 of Taiwan cobra phospholipase A2 affects its ability to enhance 8‐Anilinonaphthalene‐1‐sulfonate fluorescence
Author(s) -
Chang Longsen,
Lin Shinneren
Publication year - 1996
Publication title -
iubmb life
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.132
H-Index - 113
eISSN - 1521-6551
pISSN - 1521-6543
DOI - 10.1080/15216549600201722
Subject(s) - tyrosine , chemistry , lysine , phospholipase a2 , fluorescence , derivative (finance) , sulfonate , stacking , stereochemistry , phospholipase , phospholipase a , binding site , enzyme , biochemistry , amino acid , sodium , organic chemistry , physics , quantum mechanics , financial economics , economics
The Tyr‐3 (63) and Lys‐6 of Naja naja atra phospholipase A2 (PLA2) were modified with p‐nitrobenzenesulfonyl fluoride and 4‐chloro‐3,5‐dinitrobenzoate, respectively. Although the ability of the Lys‐modified derivative to enhance the ANS fluoresence was lower than that observed with native PLA2, the ANS‐binding affinity of the Lys‐modified derivative was similar to that of the native enzyme. Modifications on Tyr‐3 or/and Tyr‐63 of PLA2 resulted in the complete loss of its ability to enhance the ANS fluorescence. Nevertheless, the extent of O‐sulfonylation of Tyr residues was not effectively reduced by the addition of ANS. This suggests that Tyr‐3 and Tyr‐63 interact with the bound ANS in an aromatic ring‐stacking manner. Alternatively, the incorporation of a carboxydinitrophenylated group on Lys‐6 may notably perturb the nonpolarity of the ANS‐binding site.