system suitability for peptide mapping??

[rick1112]

Hi

What is the system suitability used for peptide mapping??

[danko]

Resolution and repeatability.

Best Regards

[rick1112]

Hi

Well let me elaborate on my pervious post….we had a discussion recently on this matter…one of us had a suggestion that a mix (1:2) of reference standard and test sample must be used as system suitability..
The opinion on this was divided…so arguing that this a part of sample analysis and interpretation than system suitability…
So I would like to know your opinion on this matter..? are you agreement with above suggestion??
And what is ideal or best system suitability for a peptide mapping ??

[danko]

Hi rick1112,

The suggested test (mixing a portion of the intact protein with a portion of the digest) has nothing to do with peptide mapping. The mentioned test would be more relevant to a stability indicating analysis in order to show/document that the method is capable of resolving the degradation products from the main component.
The role of the peptide mapping, on the other hand, is to document the protein’s identity by digesting it to smaller fragments. The generated fragments will always be unique for the protein in question, provided they are there (qualitatively and to some extend quantitatively) thus leaving no room for questioning the identity of the protein.
In fact it is very unusual to find a method of analysis suitable for both the intact molecule and for the tryptic digest due to the huge differences in molecule size, hydrophobicity, solubility etc.

So, if you make sure you separate the generated fragment (Resolution) and can do it every time reproducibly (comparing the chromatographic profiles to a standard/control chromatogram) then you have nothing to fear.

Best Regards