Interaction of decavanadate polyanions with proteins.
The binding of polymeric decavanadate anion [V10O28]6- with bovine serum albumin and gelatin was studied at pH 4.0 and 3.0, the region of thermodynamic stability of oligomeric vanadate anion. The binding of decavanadate anion at pH 4.0 with bovine serum albumin (BSA) and gelatin was found to be 9 and 32 gmol of decavanadate per gram mole of the proteins. The binding at pH 3.0 was found to be 12 and 38 gmol, respectively. Freshly formed BSA decavanadate precipitate was particulate in nature while that of gelatin-decavanadate made a gummy mass. This indicates a different mode of binding of decavanadate anions with globular and fibrillar proteins. Infrared spectra of the adducts endorses electrostatic binding between proteins and decavanadate. Scanning electron microscopy micrographs reveal extended crosslinked binding between decavanadate and gelatin and aggregation of the uncharged BSA-decavanadate molecules to make a granular adduct. The mode of binding was also correlated with the structure of decavanadate anions, BSA, and gelatin.
Ashraf
S M
SM
Department of Chemistry, Jamia Millia Islamia, New Delhi, India.
Rajesh
Kaleem
S
S
D000818:Animals; D000838:Anions; D002417:Cattle; D005780:Gelatin / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D008855:Microscopy, Electron, Scanning; D011485:Protein Binding; D012710:Serum Albumin, Bovine / Q000737:chemistry*; D013055:Spectrophotometry, Infrared; D013816:Thermodynamics; D014638:Vanadates / Q000737:chemistry*
D000838:Anions; D012710:Serum Albumin, Bovine; D014638:Vanadates; D005780:Gelatin