Mercadé-Prieto Ruben, Falconer Robert J, Paterson William R, Wilson D Ian
Department of Chemical Engineering, University of Cambridge, New Museums Site, Pembroke Street, Cambridge CB2 3RA, United Kingdom.
Biomacromolecules. 2007 Feb;8(2):469-76. doi: 10.1021/bm060553n. Epub 2007 Jan 23.
It is well documented in the literature that during the dissolution of whey protein gels in alkali, the gels swell to a great extent. However, the relevance of the swelling step in the dissolution process of the protein gel remains unknown. In the present article we present a systematic study on the swelling of beta-lactoglobulin gels at different alkaline pH and ionic strengths. The equilibrium swelling degree at different conditions has been modeled using a simple model developed for polyelectrolyte gels, modified to take into account the ionization of the residues in a protein. The model can describe the swelling behavior of the gels over a wide range of conditions, but it underpredicts the equilibrium swelling under conditions close to those when dissolution is observed. Dissolution is only noticeable above pH 11.5-12 and only for those gels that are swollen over a minimum degree, suggesting the existence of a dissolution threshold.
文献中已有充分记载，在碱性条件下乳清蛋白凝胶溶解时，凝胶会大幅膨胀。然而，蛋白质凝胶溶解过程中膨胀步骤的相关性仍不明确。在本文中，我们对不同碱性pH值和离子强度下β-乳球蛋白凝胶的膨胀进行了系统研究。利用为聚电解质凝胶开发的一个简单模型，并对其进行修改以考虑蛋白质中残基的电离，对不同条件下的平衡溶胀度进行了建模。该模型可以描述凝胶在很宽的条件范围内的膨胀行为，但在接近观察到溶解的条件下，它对平衡溶胀的预测偏低。溶解仅在pH值高于11.5 - 12时才明显，且仅适用于那些溶胀程度达到最小限度的凝胶，这表明存在一个溶解阈值。
