Protein Sequencing and MS
Jim.Bloom.B@bayer.com
Thu, 26 Feb 1998 13:35:28 -0500
I very much enjoyed Joe Fernandez's description of his experience with HP and
ABI sequencers and it got me thinking. We have had HP and ABI sequencers over
the last five years and no matter who the vendor, protein sequencers require an
inordinate amount of "care and feeding" and wouldn't it be nice if we could
spend time on productive things rather than keeping the sequencer happy? (I am
in another room so ours cannot see what I am typing!) I have heard an
incredible amount of hype from MS vendors and starry eyed MS "experts" over the
years about how MS can replace good old Edman. So, in case the world has
passed me by and relying on the real world experiences and hopefully lack of
axes to grind of our ABRF members let me pose the following questions regarding
Edman vs MS: 1.) lets say I am given a glycosylated protein, in solution or
on a blot, and need to identify it and any contaminants and determine if there
are any internal clips...can MS replace Edman? 2.) lets say I am doing
peptide mapping on a known protein and wish to identify all the peaks (to
verify the sequence and look for unusual post translational modifications) as
well as to determine N- or O-linked glycosylation sites and while we are at it
disulfide bonds...can I use MS alone without supplementing it with Edman and
get unambiguous results? By the way, when I am asking if MS can replace Edman
I mean to say: can a reasonably intelligent individual lacking infinite time
decipher the MS results? I will add that we have been the proud owners of a
single quad ESI-MS for five years and I know it will not do these things...so I
am also asking if some new fangled MS like these things they call "ion traps"
will do the trick or MALDI-TOF or ESI-TOF or ...(ain't technology great, the
latest and greatest is obsolete in less than five years...what happened to
"triple quads"?)
Weather inconsequential: there is a strange yellow orb in the sky over the
San Francisco Bay area today, I believe this orb has a name but I have
forgotten what it is...
Jim Bloom
Bayer Corp.
Berkeley, CA