Expression and secretion of human alpha 1(I) procollagen fragment by Hansenula polymorpha as compared to Pichia pastoris

Secretion of a human collagen alpha 1(I) chain fragment was achieved in Han senula polymorpha using the native alpha 1(I) procollagen secretory signal sequence. The N-terminal propeptide in the fragment was cleaved off during secretion, yielding the N-terminus of mature alpha 1(I) collagen. In Pichia pastoris transformants, the expression of the fragment could be detected o n RNA-level, but the product could not be determined extracellularly. After fusion of the fragment with a myc-HIS6 epitope, the intact product was fou nd intracellularly. The difference in the extracellular level of the protei n between the two expression hosts is most likely caused by difference in s ecretion efficiency. (C) 2000 Elsevier Science Inc. All rights reserved.