HIGH-LEVEL SECRETION OF 2 ANTIBODY SINGLE-CHAIN FV FRAGMENTS BY PICHIA-PASTORIS

The diagnostic and therapeutic applications of antibody single-chain F v (sFv) fragments often require large amounts of protein that can be p roblematic and expensive to obtain. Here we report the secretion of tw o sFv fragments by the yeast Pichia pastoris at levels up to 250 mg/l. Soluble sFv fragments were purified from culture supernatants in one step by affinity or metal-chelating chromatography, and were indisting uishable from their bacterially expressed counterparts in terms of aff inity. Secretion of functional sFv fragments by Pichia pastoris provid es a low cost, high yield alternative to current sFv expression system s.