Interaction of Schiff base with bovine serum albumin: site-specific photocleavage.
A Schiff-base ligand with donor/acceptor substituents viz. 2, 3-bis¿[(2-hydroxy-4-diethylamino) (phenyl) (methylene)]amino¿-2-butenedinitrile was synthesized, its binding properties with bovine serum albumin (BSA) and its site-specific photocleavage in the presence of cobaltous chloride have been evaluated. The Schiff-base ligand showed increase in absorption with a 5-nm red shift in the absorption maximum consistent with the binding of Schiff-base ligand to hydrophobic sites on the protein. The binding plot obtained from the absorption titration gives a binding constant of 6.4 +/- 0.3 x 10(4) M(-1). The CD spectrum of BSA in presence of the ligand shows that binding of the ligand leads to a change in the helicity of the protein. This ligand has been found to induce site-specific photocleavage of the protein in the presence of cobaltous chloride. The gel electrophoresis pattern of a photolyzed sample of BSA/Schiff-base ligand/cobaltous chloride shows that protein is cleaved into two polypeptide fragments, indicating site-specific binding for the ligand to the protein.
Shrivastava
H Y
HY
Chemical Laboratory, Central Leather Research Institute, Adyar, Chennai, 600 020, India.
Kanthimathi
M
M
Nair
B U
BU
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002942:Circular Dichroism; D003035:Cobalt; D066298:In Vitro Techniques; D007700:Kinetics; D010777:Photochemistry; D011485:Protein Binding; D012545:Schiff Bases / Q000737:chemistry / Q000378:metabolism* / Q000528:radiation effects; D012710:Serum Albumin, Bovine / Q000737:chemistry / Q000378:metabolism*; D013053:Spectrophotometry
D012545:Schiff Bases; D012710:Serum Albumin, Bovine; D003035:Cobalt; C018021:cobaltous chloride