Chicón Rosa, López-Fandiño Rosina, Quirós Ana, Belloque Josefina
Instituto de Fermentaciones Industriales (CSIC), Juan de la Cierva 3, 28006 Madrid, Spain.
J Agric Food Chem. 2006 Mar 22;54(6):2333-41. doi: 10.1021/jf051983s.
Beta-lactoglobulin (beta-Lg) was subjected to high pressures up to 400 MPa and proteolysis with chymotrypsin. The hydrolysates were analyzed by SDS-PAGE and RP-HPLC, and the fragments obtained were identified by ESI-MS/MS. The results obtained showed that beta-Lg was hydrolyzed by chymotrypsin in a "progressive proteolysis" manner at either atmospheric or high pressure. Proteolysis during or after high-pressure treatment showed longer and more hydrophobic peptides than proteolysis at atmospheric pressure. Chymotrypsin showed a behavior similar to that of trypsin, with some differences, probably related to the orientation of the target residues specific for each enzyme. The similarities between proteolytic fragments produced by the two enzymes support that proteolysis enhancement under high pressure depends on the substrate changes rather than the enzyme. High pressure seemed to accelerate the first steps of proteolysis, probably through dimer dissociation, while leaving portions of the molecule more resistant to the enzyme.
对β-乳球蛋白（β-Lg）施加高达400兆帕的高压，并使用胰凝乳蛋白酶进行蛋白水解。通过SDS-PAGE和RP-HPLC对水解产物进行分析，并通过ESI-MS/MS鉴定获得的片段。所得结果表明，β-Lg在常压或高压下均以“渐进性蛋白水解”方式被胰凝乳蛋白酶水解。高压处理期间或之后的蛋白水解产生的肽段比常压下的蛋白水解产生的肽段更长且疏水性更强。胰凝乳蛋白酶表现出与胰蛋白酶相似的行为，但存在一些差异，这可能与每种酶特异性作用的靶残基的取向有关。两种酶产生的蛋白水解片段之间的相似性表明，高压下蛋白水解的增强取决于底物的变化而非酶的变化。高压似乎加速了蛋白水解的第一步，可能是通过二聚体解离，同时使分子的某些部分对酶更具抗性。
