Changes in Chymotrypsin Hydrolysis of -Lactoglobulin A Induced by High Hydrostatic Pressure

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• 作者：Rosa Chic&oacute ; n ; Rosina L&oacute ; pez-Fandiñ ; o ; Ana Quir&oacute ; s ; and Josefina Belloque
• 刊名：Journal of Agricultural and Food Chemistry
• 出版年：2006
• 出版时间：March 22, 2006
• 年：2006
• 卷：54
• 期：6
• 页码：2333 - 2341
• 全文大小：269K
• 年卷期：v.54,no.6(March 22, 2006)
• ISSN：1520-5118

文摘

-Lactoglobulin (-Lg) was subjected to high pressures up to 400 MPa and proteolysis withchymotrypsin. The hydrolysates were analyzed by SDS-PAGE and RP-HPLC, and the fragmentsobtained were identified by ESI-MS/MS. The results obtained showed that -Lg was hydrolyzed bychymotrypsin in a "progressive proteolysis" manner at either atmospheric or high pressure. Proteolysisduring or after high-pressure treatment showed longer and more hydrophobic peptides than proteolysisat atmospheric pressure. Chymotrypsin showed a behavior similar to that of trypsin, with somedifferences, probably related to the orientation of the target residues specific for each enzyme. Thesimilarities between proteolytic fragments produced by the two enzymes support that proteolysisenhancement under high pressure depends on the substrate changes rather than the enzyme. Highpressure seemed to accelerate the first steps of proteolysis, probably through dimer dissociation,while leaving portions of the molecule more resistant to the enzyme.Keywords: -Lactoglobulin; high hydrostatic pressure; proteolysis; chymotrypsin; milk whey proteins