Interaction of chlorpromazine with milk proteins |
| |
Authors: | Bhattacharyya Jaya Das Kali P |
| |
Institution: | (1) Protein Chemistry Laboratory, Department of Chemistry, Bose Institute, 92/3 Acharyya Prafulla Chandra Road, Calcutta, 700 009, India |
| |
Abstract: | The mode and nature of the binding of chlorpromazine (CPZ), a psychotropic drug, with milk proteins – -lactalbumin (with substantial amounts of -helix, -sheet and random coil), -lactoglobulin (a major -sheeted protein) and s-casein (a random coiled protein) have been studied spectrofluorometrically and spectropolarimetrically. The binding affinity of CPZ for unfolded proteins is comparatively less than that of folded proteins although the number of binding sites is smaller in the latter case, due to the greater extent of binding of CPZ for folded proteins. Thermodynamic analysis reveals that CPZ binds to -lactalbumin and s-casein in an endothermic (Ho is positive) and hydrophobic manner but with -lactoglobulin in an exothermic (Ho is negative) manner. Far UV Circular dichroic studies reveal that CPZ increases the secondary structure of the major -sheeted protein, -lactoglobulin possibly by increasing the relative contact orders (non-local contacts) within the residues. On the other hand, for proteins possessing random coil, it increases the unfolded state of the protein. CPZ does not affect local contacts in a-helix when its interaction is compared with a major -helical protein, myoglobin. |
| |
Keywords: | chlorpromazine alpha-lactalbumin beta-lactoglobulin alpha-casein |
本文献已被 PubMed SpringerLink 等数据库收录! |
|