title: Effect of limited enzymatic hydrolysis on linoleic acid binding properties of β-lactoglobulin.
abstract: β-Lactoglobulin (BLG) is a member of lipocalin family, proteins with ability to bind small hydrophobic ligands, such as retinol, vitamins and fatty acids. Moreover, BLG is susceptible to protease action producing a wide range of polypeptides depending on the hydrolysis degree (HD). In the present work, the effect of limited enzymatic hydrolysis on fatty acid binding properties of BLG was studied. Linoleic acid (LA) was used as a model fatty acid. Limited enzymatic hydrolysis was performed using α-chymotrypsin immobilised on agarose microparticles. BLG hydrolysates were produced at HD: 1%, 3% and 5%. In order to determine the influence of HD on BLG molecular weight SDS-PAGE was used. BLG structural modification and LA binding properties were monitored by means of fluorescence spectroscopic techniques. The increase in HD produced: (i) a BLG degradation and a molecular weight distribution of BLG hydrolysates and (ii) an increased exposition of buried hydrophobic residues, however it was observed a decrease in surface hydrophobicity possibly due to a deterioration of hydrophobic protein domains. It was observed that enzymatic hydrolysis treatment produced a decrease in BLG ability for binding LA. It was concluded that limited enzymatic hydrolysis could deteriorate the specific site on BLG structure necessary for binding LA.
authors.affiliation: Grupo de Biocoloides, Instituto de Tecnología de Alimentos, Universidad Nacional del Litoral, 1 de Mayo 3250 (3000), Santa Fe, Argentina.
authors.forename: Osvaldo E
authors.initials: OE
authors.lastname: Sponton
authors.forename: Adrián A
authors.initials: AA
authors.lastname: Perez
authors.forename: Carlos
authors.initials: C
authors.lastname: Carrara
authors.forename: Liliana G
authors.initials: LG
authors.lastname: Santiago
mesh_terms: D002918:Chymotrypsin / Q000737:chemistry*; D006868:Hydrolysis; D057927:Hydrophobic and Hydrophilic Interactions; D007782:Lactoglobulins / Q000737:chemistry*; D019787:Linoleic Acid / Q000737:chemistry*; D011485:Protein Binding; D013050:Spectrometry, Fluorescence
chemical_list: D007782:Lactoglobulins; D019787:Linoleic Acid; D002918:Chymotrypsin; C117608:alpha-chymotrypsin
keywords: Binding properties; Enzymatic hydrolysis; Fluorescence spectroscopy; Linoleic acid; α-Chymotrypsin; β-Lactoglobulin