Low pth lys, on an older machine like the 477, can probably be fixed by
doing a DTT wash of the valve blocks. A PEABD service engineer showed us
this and it boosts the recovery of other residues like trp and the other
basics too.
It can also be caused by bad THF in the A buffer (peroxide formation).
Other less likely causes could be an old column and, I think, bad R4.
If you have never DTT washed your valve blocks, start there.
Dick Cook
I'm sorry. I made a mistake. The problem with the lysine is only on the 477.
Charles
_______________________________________________________________________________
Subject: Re: Prot Seq: Low Lysine
From: CHARLES MCNEMAR
Date: 02/23/1998 07:43
When I run B-lactoglobulin on the 477 and 494, I get about 95% repetitive yield
on both instruments. On the 494, the K-8 is about 30% of the M-7 and G-9.
Does anyone have any experience solving this problem?
Charles McNemar, Ph.D.
Associate Principal Scientist
Schering-Plough Research Institute
2015 Galloping Hill Road
Kenilworth, NJ 07033
908-298-7194
FAX: 908-298-4844
E-mail: charles.mcnemar@spcorp.com