Date: Mon, 20 Jan 1997 14:11:37 +0000 (GMT)
From: KNIERMAN MICHAEL D <KNIERMAN_MICHAEL_D@Lilly.Com>
Subject: RE: TFMSA modification
To: Recipients of ABRF List <abrf@aecom.yu.edu>
Ken,
Could you be seeing very strong non-covalent bonding between Lys or Arg
and the TFMSA counter ion? I don't know if this would survive the HPLC
step. I am thinking this would be similar to the Na adduct formation in
MALDI. Does anyone else have a comment this?
Michael D. Knierman
Eli Lilly
knierman@lilly.com
Disclaimer: Any opinions stated above are my opinion and do not reflect any
position of Eli Lilly and Co.
<Dear everybody,
< I am trying to determine whether TFMSA (trifluoromethanesulfonic
<acid) could be useful for deglycosylating proteins for subsequent mass
<spectrometry analysis. I found evidence of RP-HPLC -stable when I
<tested to see whether lysozyme was modified, that corresponds to a
<gain in MW by MALDI of about 7 molecules of TFMSA per lysozyme. Has
<anyone heard of covalent bond formation starting from neat, anhydrous
<TFMSA upon addition to protein dried onto a tube (following acetone
<precipitation)? I am leaving the protein exposed to TFMSA for only 5
<min. on ice prior to neutralization (on ice) with aliquots of
<triethylamine prior to dilution into reversed phase solvents prior to
<separation. This roughly corresponds to treatments described in JBC
<265:6854; JBC 267:25494 and JBC 263:19709, except that that I
<substituted triethylamine for pyridine. In the above papers, no MS
<data were reported.
< Any comments would be useful. I plan also to investigate
<deglycosylating enzymes according to published protocols.
< Thanks,
< Ken Parker
< kcp@nih.gov