The interaction of 8-anilinonaphthalene-1-sulfonate with His-47 of Taiwan cobra phospholipase A2 perturbing by the binding of calcium ion.
The 8-anilinonaphthalene-1-sulfonate (ANS) fluorescence intensity of ANS-Naja naja atra (Taiwan cobra) phospholipase A2 (PLA2) complex increased with the addition of Ca2+, but the observed fluorescence enhancement markedly decreased after methylation of His-47 in PLA2 molecule. However, the binding affinities of methylated PLA2 for ANS and Ca2+ were similar to or even greater than those observed with native PLA2. These results, together with the finding that ANS electrostatically interacted with His-47 of PLA2, suggest that the increase in the intensity of ANS fluorescence upon the addition of Ca2+, in part, arises from the ionic interaction of His-47 with ANS being perturbed by the binding of Ca2+.
Chang
L S
LS
Department of Biochemistry, Kaohsiung Medical College, Taiwan, ROC.
Chou
L
L
Lin
S R
SR
Chang
C C
CC
D000817:Anilino Naphthalenesulfonates / Q000378:metabolism*; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D004546:Elapid Venoms / Q000201:enzymology*; D005453:Fluorescence; D005456:Fluorescent Dyes; D006632:Histamine / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2
D000817:Anilino Naphthalenesulfonates; D004546:Elapid Venoms; D005456:Fluorescent Dyes; C027132:1-anilino-8-naphthalenesulfonate; D006632:Histamine; D010741:Phospholipases A; D054467:Phospholipases A2; D002118:Calcium