First of all,pay heed to Nadine Ritter's questions.It is pretty much what I
do,I tell the
investigators the facts,and let them deide what is proper.I have been doing
amino acid
analysis,which is the most straightforward method of quality control.Mass
spec analysis of
MAPs has been done successfully before,but if your amino acid analysis is
bad,the Mass spec
and sequencing,as well will be worse.The HPLC profile is very indicative of
what you have.
Steric problem occur after five or six residues,and the more branches the
worse is the
problem.I recommend to try four and eight branch synthesis,and see how they
look.In most
cases eight-branch MAPS are not tried anymore.Longer reaction times,rather
than repeated
couplings are just as effective.Capping is not so simple in Fmoc
chemistry,and you would
have to see if it would help.Change of solvent(s) during the synthesis,to
keep the chain
from bending backward should help.And,finally,I tried HPLC with a
denaturant(urea),and
some separations improved.I would do away with questionable MAPs any
time,in favor of
conjugation of a pure peptide conjugated to a carrier protein.
"alex bell" <ehjb@musica.mcgill.ca>@aecom.yu.edu> on 05/12/2000 09:06:00 PM
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Subject: quality control MAP peptide for antibodies
Dear All,
What are some of the quality controls that are employed for MAP synthetic
peptides for raising antibodies?
How much branching isÝrecommended?
Are missed amino acids (deletion sequences) at a low frequency a concern?
Triple coupling synthesis procedure employed but no capping.
Mass spect analysis? Amino acid analysis? Sequence (Edman or MS/MS)
analysis?
Thanks in advance,
ÝÝÝ alex
Alexander Bell
McGill University
Anatomy & Cell Biology
Strathcona Bldg.
3640 University
Montreal, Qc.Ý H3A 2B2
phone (514) 398-1393
faxÝÝÝÝÝ(514) 398-5047
email ehjb@musica.mcgill.ca
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