Characteristics of ß-Lactoglobulin Binding to the All-Trans-Retinal Moiety Covalently Immobilized on Celite^TM

¹ Southeast Dairy Foods Research Center, Department of Food Science, North Carolina State University, Raleigh 27695-7624

All-trans-retinal was covalently immobilized on Celite^TM and investigated as a bioselective adsorption matrix for ß-lactoglobulin. Two types of Celite^TM supports were compared, indicating the best performance with 100/120 mesh, type R648. The R648 matrix yielded a high concentration (9.2 µmol/ml) of the ligand when the derivative was produced, and the derivatized matrix exhibited the best retention of ß-lactoglobulin. Binding of ß-lactoglobulin to the immobilized trans-retinal matrix is biospecific, but the affinity is dependent on pH and ionic strength. -Lactalbumin is not bound to this bioselective adsorbant, so its elution was not retarded or affected by pH or buffer concentration. Affinity for ß-lactoglobulin was optimal at pH 5.14; a dissociation constant of 2.7 µM was obtained in .1 M buffer solutions. At pH 7.0, the affinity decreased 44-fold, and, below pH 3.5, no binding occurred. The estimated loading capacity based on chromatographic data was approximately 14 g/L (.75 µmol/ml) of support.

Key Words: immobilized all-trans-retinal • ßbeta;-lactoglobulin binding • bioselective • adsorption

Submitted on November 2, 1992
Accepted on February 17, 1993

This article has been cited by other articles:

				M. R. Etzel Manufacture and Use of Dairy Protein Fractions J. Nutr., April 1, 2004; 134(4): 996S - 1002S. [Abstract] [Full Text] [PDF]

				H. K. Vyas, J. M. Izco, and R. Jimenez-Flores Scale-Up of Native {beta}-Lactoglobulin Affinity Separation Process J Dairy Sci, July 1, 2002; 85(7): 1639 - 1645. [Abstract] [Full Text] [PDF]