PEG thiazolidine-2-thione, a novel reagent for facile protein modification: conjugation of bovine hemoglobin.

A novel PEG linker that employs a thiazolidine-2-thione group has been synthesized. Kinetic studies done on this compound demonstrate a relatively long half-life compared to those of traditional succinimidyl linkers. This new PEG derivative reacts with proteins under mild conditions and was utilized to conjugate bovine hemoglobin (bHb) to provide a PEG amide-linked protein. The physical characteristics of this conjugate were compared with those of the known PEG carbamate-linked bHb.