rhGH-affinity-peptide selection using combinatorial libraries.

M.M. MARANI; M. C. MARTÍNEZ-CERON; G. FORNO; F. ALBERICIO; O. CASCONE; S. A. CAMPERI

Puerto Madryn

Congreso; 46 Annual Meeting Argentine Society for Biochemistry and Molecular Biology; 2010

Growth hormone (hGH) is used in medicine to treat children´s growth disorders and adult growth hormone deficiency. High purity is necessary for its parenteral administration. Thus, downstream processing should be optimized to obtain higher yields and low cost processes. Affinity Chromatography (AC) is considered an efficient method for protein purification in complex mixtures. Short peptides are ideal ligands for industrial separations because of its low cost, high stability and easy manufacture. We synthesized a peptide combinatorial library XXOXXOOO (O=fixed and X=variable positions) using Divide-couple-recombine (DCR) method that allows obtaining a library with all possible combinations of amino acids in the form of "one bead-one peptide". Peptide ligands can be selected from library screening. We have developed a rapid and non-expensive strategy for peptide identification contained on positive beads, by using MALDI-TOF-MS, and 4-hydroxymethylbenzoic acid. We selected more than 50 peptides with rhGH affinity using this strategy. The peptides showed consensus sequences. Those peptides could be used not only as affinity ligands for new strategies development based on AC rhGH purification but also as diagnostic-rhGH-kits ligands. This kind of systems could improve cost/benefit ratio obtaining economically competitive products.