凡是蛋白质在等电点时必然沉淀吗?为什么?
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凡是蛋白质在等电点时必然沉淀吗?为什么?
凡是蛋白质在等电点时必然沉淀吗?为什么?
凡是蛋白质在等电点时必然沉淀吗?为什么?
不一定会沉淀,因为蛋白质表面有亲水基团,只是在等电点的时候颗粒无电荷间的排斥作用,易凝集成大颗粒,因而最不稳定,溶解度最小,易沉淀析出.
是的，就这一点来看是符合化学原理的
The pI value can affect the solubility of a molecule at a given pH. Such molecules have minimum solubility in water or salt solutions at the pH which corresponds to their pI and often precipitate out ...
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The pI value can affect the solubility of a molecule at a given pH. Such molecules have minimum solubility in water or salt solutions at the pH which corresponds to their pI and often precipitate out of solution. Therefore, proteins will not necessarily precipitate at PI.Because the composition amino acids for given proteins are different, proteins can thus be separated according to their isoelectric point (overall charge) on a polyacrylamide gel using a technique called isoelectric focusing, which uses a pH gradient to separate proteins. Isoelectric focusing is also the first step in 2-D gel polyacrylamide gel electrophoresis.
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在等电点时，蛋白质分子以双极离子存在，总净电荷为零,颗粒无电荷间的排斥作用,易凝集成大颗粒，因而最不稳定，溶解度最小，易沉淀析出。
等电点时溶解度最小。