Why the band at wrong molecular weight?

[Gorbin]

The single band detected by WB is about 50kDa smaller than it should be. What are the possible reasons other than complete degradation?

[admin]

Hi Gorbin,
how big is your protein? Also 50kDa is quite a bit of a difference, could be proteosomal degradation, splicing, or other like a gel problem or ladder issue.

Have you checked your protein sequence / protein published information to see if it behaves funny?

[Gorbin]

Thank you for your kind suggestion.
The protein here is actually HIF1-alpha, which is extremely vulnerable to degradation. In literature it appears a band at around 120 kDa. But you know, most people won't show the entire gel, so I have no idea if they also have a 70kDa band. It is possible that the 70kDa band is the degraded form of HIF1-alpha. Is there any way to check it, rather than blindly taking more care of prevention of protein degradation? Thanks!