论文部分内容阅读
蛋白质如同氨基酸那样,是两性电解质.其游离基团除末端氨基和末端羧基外,主要由侧链的游离基团所构成.在电泳分离蛋白质时若能事先算出待分离蛋白质的等电点(pI),然后据此调整溶液的pH就能使分离的效果更为理想.如有三种蛋白质,pI分别为5、6、7.若将溶液PI调至6,则电泳时第二种蛋白质不移动,第一、三种蛋白质分别向正、负极移动.此时可将样品点在电泳支持物中间.若溶液pH调至5(或7)则样品应点在支持物靠正(或负)极一端,否则结果将不理想.由于蛋白质可能有相当多带非α-氨基(如赖氨酸残基中的∑-基氨,精氨酸残基的胍基和组氨酸的咪唑基等能游离成正离子基团)和羧基
Proteins, like amino acids, are amphoteric electrolytes whose free radicals are mainly composed of free radicals in the side chain except for the terminal amino group and the terminal carboxyl group.If electrophoretic separation of proteins, the isoelectric point (pI ), And then adjust the pH of the solution to make the separation effect is more ideal.If there are three proteins, pI were 5,6,7 .If the solution is adjusted to 6 PI, the second protein electrophoresis does not move , The first and the third proteins move to the positive and negative, respectively, and the sample can be spotted in the middle of the electrophoresis support. If the pH of the solution is adjusted to 5 (or 7), the sample should be placed on the positive (or negative) End, otherwise the result will be unsatisfactory.Because the protein may have a considerable number of non-α-amino (such as lysine residues in the Σ-amino, arginine residues of guanidine and histidine imidazole and other can Free into a positive ion group) and a carboxyl group