Process for purifying recombinant <i>Plasmodium falciparum </i>circumsporozoite protein

摘要

The present invention relates to processes for purifying high-quality recombinant Plasmodium falciparum circumsporozoite protein at high yields.

主权项

1. A process for purifying recombinant P. falciparum circumsporozoite protein (rCSP), said process comprising:
(a) obtaining a bacterial cell lysate preparation comprising recombinant P. falciparum circumsporozoite protein dimer; (b) separating the bacterial cell lysate preparation of step (a) into a soluble fraction comprising the recombinant P. falciparum circumsporozoite protein dimer, and an insoluble fraction; (c) separating the recombinant P. falciparum circumsporozoite protein dimer in the soluble fraction of step (b) from host cell proteins in the soluble fraction; and (d) subjecting the recombinant P. falciparum circumsporozoite protein dimer obtained in step (c) to preferential reducing conditions, wherein the preferential reducing conditions reduce intermolecular disulfide bonds and preserve intramolecular disulfide bonds in the rCSP; thereby obtaining purified recombinant rCSP, without a denaturation or refolding step, wherein the recombinant P. falciparum circumsporozoite protein obtained includes the most N-terminal cysteine, said most N-terminal cysteine corresponding to the cysteine at position 25 as set forth in SEQ ID NO: 1, and wherein not more than about 10% of the purified recombinant P. falciparum circumsporozoite protein obtained is dimerized, and not more than about 10% of the purified recombinant P. falciparum circumsporozoite protein obtained is present as high molecular weight aggregates.