The effect of glycosylation on emulsifying and structural properties of bovine beta-casein.
A number of attempts have been made to improve the functional properties of milk proteins by chemical modifications. One of such modifications is glycosylation which was carried out to determine the effect of covalent binding of glucose molecules to beta-casein (beta CN) on its emulsifying properties. It was found that up to six molecules of glucose were bound to one molecule of beta CN. Glycosylated beta CN produced smaller emulsion droplets than the intact beta CN. Increases in emulsion-forming and -stabilizing properties were observed. A prerequisite of proteins to form emulsions is their adsorption onto oil/water interface. Therefore the secondary structure of intact and glycosylated beta CN, both in solution and adsorbed onto a hydrophobic teflon/water interface also were studied by far-ultra violet circular dichroism (CD). It appeared, that after glycosylation the degree of helicity of intact beta CN decreased and the incorporation of glucose moieties most likely resulted in a type beta-turn formation after adsorption onto the interface.
Warmia and Masuria University of Olsztyn, Department of Food Biothemistry, Pl. Cieszynski 1, PL-10-726 Olsztyn, Poland.
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M
Darewicz
J
J
Dziuba
D000327:Adsorption; D000818:Animals; D002364:Caseins / Q000737:chemistry*; D002417:Cattle; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002942:Circular Dichroism; D004655:Emulsions; D005260:Female; D006031:Glycosylation; D008892:Milk / Q000737:chemistry*; D010316:Particle Size; D017433:Protein Structure, Secondary; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013056:Spectrophotometry, Ultraviolet; D013329:Structure-Activity Relationship
D002364:Caseins; D004655:Emulsions