Re: Synthesis of phosphopeptides
Angela c. Murphy (acmurphy@helix.nih.gov)
Thu, 10 Sep 1998 15:20:49 -0400 (EDT)
The expensive way: Weigh out 1 mmole Fmoc-Ser(PO(OBzl)-OH into a Ser
cartridge. Do this twice. Modify your double couple RV cycle so that
coupling time is at least one hour each time, and maybe add a 3rd
piperidine deprotection cycle. Run the synthesis, using the modified
double couple cycle for pSer.
The less expensive way: Modify a single couple RV cycle and take a resin
sample after the coupling. Do a Ninhydrin test to see if you need to re-
couple.
The least expensive way: Take the resin out of the synthesizer after the
coupling of the residue immediately preceding the pSer. Deprotect it and
take a resin sample for Ninhydrin. Based on the substitution calculated
from the Ninhydrin test, weigh out a 4-fold molar excess of the pSer, and
mix with the appropriate amount of HBTU/HOBt and DIEA. Add to the resin,
put on a shaker and shake for 1-2 hours. Do Ninhydrin test to see if
coupling is complete. If it is, put the resin back into the 431 and
continue the synthesis. If it is not, recouple.
Hope this helps.
Angela C. Murphy
On Thu, 10 Sep 1998, Bao-Shiang Lee wrote:
> Hi everyone,
>
> Need a protocol to synthesize a phosphopeptide using
> Fmoc-Ser(PO(OBzl)-OH)-OH with ABI431A. Thanks.
>
> Bob Lee, UIC
>
*******************************************
Angela C. Murphy, Chemist
Lab. of Cell Biology, NHLBI, NIH
3 Center Drive, MSC 0301, Rm. B1-22
9000 Rockville Pike
Bethesda, MD 20892-0301 USA
tel.: (301) 496-2324
fax: (301) 402-1519
email: acmurphy@helix.nih.gov
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