Spectrofluorimetric study of the interaction of methyl-parathion with fish serum albumin

Fish Physiol Biochem. 2010 Sep;36(3):427-433. doi: 10.1007/s10695-009-9312-z. Epub 2009 Mar 18.

Abstract

The interaction of methyl-parathion with the albumin of Piaractus mesopotamicus (Holmberg 1887) (= pacu), a fish species typical of Brazilian rivers, was studied and the results compared with known values for human and bovine albumin obtained in an earlier investigation. Methyl-parathion (O,O-dimethyl O-p-nitrophenyl phosphorothioate) is an organophosphorous pesticide still used in agriculture and fish farming in many countries. The fluorescence quenching technique with tryptophan as a natural probe was used to detect for the presence of methyl-parathion. Fluorescence can be mathematically expressed by the Stern-Volmer equation to calculate quenching constants, and changes in the behavior of Stern-Volmer curves at different temperatures indicate the nature of the mechanism causing the quenching. Our results indicate that methyl-parathion forms a complex with fish albumin. The estimated association constant is 9.73 x 103 (+/- 4.9 x 102) M(-1) at 25 degrees C.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Fishes / metabolism*
  • Fluorescence
  • Humans
  • Insecticides / metabolism*
  • Methyl Parathion / metabolism*
  • Models, Biological
  • Serum Albumin / metabolism*
  • Species Specificity
  • Spectrophotometry, Ultraviolet
  • Temperature
  • Tryptophan

Substances

  • Insecticides
  • Serum Albumin
  • Methyl Parathion
  • Tryptophan