Shin-etsu Chemical Co., Ltd.

Haruaki Yajima

Nobutaka Fujii

Tatsuhiko Honguu

Gilberto M Guterres

Shinya Kiyama

The invention provides a method and reagent for the modification of polypeptides useful in experimental research in the area of genetic engineering starting from a polypeptide such as hCCK-33 in an unsulfated form which contains Tyr and Ser and/or Thr residues by first protecting the amino-groups in the starting polypeptide, masking the OH-groups in the Ser and/or Thr residues and selectively sulfating the OH-groups in the Tyr residues after deprotection.

Method of selectively sulfating peptides

Reagent for removing protective groups employed in peptide synthesis comprises a combination of hard acid and soft base. The hard acid is trialkylsilyltrifluoromethanesulphonate R.sub.3 SiO.sub.3 SCF.sub.3 and the soft base is ether. The reagent provides high efficiency of deprotection and has a low tendency to cause side reaction.

Growing community of inventors

Toyonaka, Japan

Haruaki Yajima