A solid phase synthesis of the polypeptide corresponding to the 1-42 s
equence of beta-amyloid protein that accumulated in brain cells during
Alzheimer's disease was performed using Fmoc strategy. Two alternativ
e approaches to the synthesis, stepwise elongation of the peptide chai
n and fragment coupling, were compared, and the advantage of the latte
r approach was shown. Effects of various factors (solvents, reagents f
or deprotection of alpha-amino functions, and substitution level of po
lymer carrier) on the synthesis was studied. The appropriate condition
s of HPLC for an analysis of the homogeneity bf the beta A4(1-42) pept
ide, as well as the conditions of its gel chromatography on Sephadex G
-50 providing the preparation of the end product of 90-95% purity acco
rding to HPLC were found.