Re: Regarding digestion with aminopeptidases

MUJ (MUJ@novo.dk)
Fri, 6 Feb 1998 16:38:25 +0100



Dear ABRF member,

I have a derivative of a protein which apparently is N-terminally
racemized. I would like to show that the derivative is not cleaved by
an aminopeptidase whereas the protein itself is. I have tried
aminopeptidase M from both Boehringer Mannheim and Sigma but none of
them are able to cleave the protein itself with the condition I have
used followed by MALDI MS analysis. As far as I know aminopeptidase M
should be able to distinguish between L and D forms.

Do you have any suggestions for a good commercial test proteins and
conditions under which you know that the aminopeptidase M works ?
Alternatively, if you have any recommendations for digestion
conditions in general for aminopeptidase M or another aminopeptidase
which may distinguish between L and D forms then it would be greatly
appreciated. I would like to analyse the digestion mixture directly by
MALDI MS.

Yours sincerely,

Mette Uve Jars, Ph.D.
Protein Chemistry, Ba (202)
Biologics Development
Health Care Development
Novo Nordisk A/S

Tel. + 45 4442 7532
Fax: + 45 4442 1014