The most straightforward approach (which also permits to avoid racemization
at C-terminal His) is to synthesize the protected segment
VTSAPDTRPAPGSTAPPAHG (5 prolines guarantee its high solubility!),
and to couple it 4 times to
VTSAPDTRPAPGSTAPPAH-resin,
and, finally, to add the N-terminal glycine
G-->4x(VTSAPDTRPAPGSTAPPAHG)-->VTSAPDTRPAPGSTAPPAH-resin
It's quite likely that your customers do not mind if you add an extra Gly
at the C-terminus of the polypeptide chain. If so, you can save a lot of
time synthesizing 'monomer'-resin only once using an appropriate linker
(SASRIN or the like) as follows:
G-->4x(VTSAPDTRPAPGSTAPPAHG)-->VTSAPDTRPAPGSTAPPAHG-linker-resin
Best regards,
Igor
Laboratory of Peptide Chemistry
Branch of Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry
Pushchino, Moscow Region
142292, Russian Federation
E-mail: <rodionov@fibkh.serpukhov.su> or <Igor_Rodionov@iname.com>
Fax: (0967)-79-05-27
Phones: (0967) 73 54 42; private: (0967) 73 58 26