Interaction of alphaS1-casein with curcumin and its biological implications.
alpha(S1)-Casein is one of the major protein components of the casein fraction of milk. Curcumin (diferuloyl methane), the major curcuminoid, constituting about 2-5% of turmeric (Curcuma longa ) is the active ingredient with many physiological, biochemical, and pharmacological properties. On the basis of spectroscopic measurements, it is inferred that curcumin binds to alpha(S1)-casein at pH 7.4 and 27 degrees C with two binding sites, one with high affinity [(2.01 +/- 0.6) x 10(6) M(-1)] and the other with low affinity [(6.3 +/- 0.4) x 10(4) M(-1)]. Binding of curcumin to alpha(S1)-casein is predominantly hydrophobic in nature. The anisotropy of curcumin or conformation of alpha(S1)-casein did not change on interaction. The stability of curcumin in solution at pH 7.2 was enhanced on binding with alpha(S1)-casein. The chaperone-like activity of alpha(S1)-casein gets slightly enhanced on its binding to curcumin. The ability of curcumin to protect erythrocytes against hemolysis was not affected due to curcumin- alpha(S1)-casein interaction. The two binding sites of alpha(S1)-casein for curcumin, along with enhanced solution stability on interaction, may offer an alternative approach in physiological and nutritional applications.
Sneharani
Athahalli H
AH
Department of Protein Chemistry and Technology, Central Food Technological Research Institute (A Constituent Laboratory of the Council of Scientific and Industrial Research), Mysore 570020, India.
Singh
Sridevi Annapurna
SA
Appu Rao
A G
AG
D000818:Animals; D001665:Binding Sites; D002364:Caseins / Q000737:chemistry*; D002417:Cattle; D003474:Curcumin / Q000737:chemistry* / Q000494:pharmacology*; D004912:Erythrocytes / Q000187:drug effects; D006461:Hemolysis / Q000187:drug effects; D007700:Kinetics; D008968:Molecular Conformation; D011485:Protein Binding
D002364:Caseins; D003474:Curcumin