There's nothing anomalous about your observed Glu-N cleavage. The
Boehringer-Mannheim enzyme package insert describes this phenomenon.
Their suggestion, and my own experience backs them up, is to drastically
lower the protease concentration (instead of 1/50, maybe go as low as
1/200-1/500) to minimize the Glu-N activity.
Mike Klein
Amgen, Inc.
> ----------
> From: Adams, Greg[SMTP:GAdams@mabioservices.com]
> Sent: Wednesday, April 22, 1998 11:39 AM
> To: Recipients of ABRF List
> Subject: Asp-N Cleavage
>
> Hi,
>
> I have a protein that I digested with Asp-N (2% w/w for 24 hours). I
> suspect that I am also getting some minor cleavage at the N-terminal
> side of Glutamic Acid. Has anyone experienced this anomalous cleavage
> when using Asp-N.
>
> Greg Adams
> MA BioServices
>