RE: Protein Sequencing and MS
Joseph Fernandez (fernaj@rockvax.rockefeller.edu)
Fri, 27 Feb 1998 08:53:05 -0500 (EST)
Regarding the question of Edman versus MS, why is the word VERSUS
continually kept between the two words. I think most people should
consider them Edman AND MS, as the two techniques compliment each other
excellently for primary characterization of Proteins, the bottom line for
what most people want these techniques for. While Edman is weaker in
certain areas such as slower time, lower sensitivity, and more difficulty
with post-translational modifications MS has other disadvantages such as
differentiating between ILE/LEU and GLN/LYS, reading the amino terminus of
a protein (provided it's blocked), and obtaining longer contiguous
sequence. My opinion is you tend to get faster data for identification of
known proteins by MS, but for novel or homologous proteins you still need
primarily Edman. By limiting yourself to solely one technique or the other
you are probably obtaining less data to support your observations or
claims.
In answer to Jim's questions, you probably would want both
techniques. Using both Edman AND MS you get more clear data and a more
definitive answer. After a while the question of Edman versus MS becomes
rhetorical with no meaning. Gary summed it all up by saying "I guess in
the final analysis,there are no guarantees in science no matter how
sophisticated the hardware."
My participation on the bulletin board has almost solely been Edman
sequencing and Enzymatic digestions. It's where my strength is and how I
best contribute to the ABRF. Although I am not a mass spectrometrist, I
have great respect for the power of this technique to answer many protein
questions. Who knows, maybe 10 or 20 years from now someone will saying MS
is dead only to find there are certain answers that cannot be answered
adequately without it.
Joe
Weather inconsequential: Looks like a springltime weekend on Long Island
coming up and I plan to spend the entire time with the family and actually
forget science for a few days.
Joseph Fernandez
Associate Director
The Rockefeller university
Protein/DNA Technology Center
1230 York Ave. New York, NY 10021
Phone: (212)-327-8869
FAX : (212)-327-8620
email: fernaj@rockvax.rockefeller.edu
Lab Web Page: http:\\pdtc.rockefeller.edu