it's not degradation (proteases work less efficiently at ~90C, but will be a disaster at ~55C at which proteases have reduced activity but protein substrates begin to open structure and give much higher accessibility), but precipitation because proteins lose native structure under heating. This is why SDS or LDS loading bf needs to be added before heating. 1g sds binds to 14g proteins, 10ul sds loading bf is supposed to be enough wrap all proteins in the sample as they are so low. the only problem of heating is that the salts will also be concentrated, which will affect protein migration in the sds-page. tca might not work well when proteins are so low, which is a common problems for any ogranic solution-based precipitation. Besides, it needs extra step to adjust ph, but it might be worth a try. A column can also be used, e.g., YM-30. but use loading bf go through the column first to saturate/block the filter membrane, and also don't forget use h2o to wash it so as to get rid of extra sds that forms micelle that can potentially block the flow. pls let us know which method works well for you. we can also learn more by reading your experience.Thanks!
a but is to proteins 我的buffer里还有2%的SDS应该问题不大。非常感谢你讲的这么详细!
【在 d********n 的大作中提到】 : it's not degradation (proteases work less efficiently at ~90C, but will be a : disaster at ~55C at which proteases have reduced activity but protein : substrates begin to open structure and give much higher accessibility), but : precipitation because proteins lose native structure under heating. This is : why SDS or LDS loading bf needs to be added before heating. 1g sds binds to : 14g proteins, 10ul sds loading bf is supposed to be enough wrap all proteins : in : the sample as they are so low. : the only problem of heating is that the salts will also be concentrated, : which will affect protein migration in the sds-page.