Application of preparative high-performance liquid chromatography to the purification of a fetal ovine insulin-like growth factor II: N-terminal sequence determinations using two different carriers

• Published in: Journal of chromatography. Biomedical applications 1990, Vol.533, p.35-46
• Main Authors: Straczek, J., Heulin, M.H., Chenut, A.M., Belleville, F., Nabet, P., Denoroy, L., Barenton, B., Blanchard, M., Charrier, J., Martal, J.
• Format: Article
• Language: English
• Subjects: Analytical, structural and metabolic biochemistry; Biological and medical sciences; Fundamental and applied biological sciences. Psychology; Proteins
• ISSN: 0378-4347
• DOI: 10.1016/S0378-4347(00)82185-4

A highly efficient procedure for the purification to homogeneity of an ovine fetal insulin-like growth factor II (IGF II) is described. Fetal sheep serum was used as the source material, and the bioactivity was followed throughout purification by an IGF II radioreceptor assay. Ovine IGF II was isolated by a combination of gel permeation, ion-exchange chromatography and reversed-phase high-performance liquid chromatography. The amino-terminal sequence of the first 36 amino acid residues was compared using two supports (polyethylenimine and polybrene) as carrier for protein sequencing. Ovine fetal IGF II was found to differ from human IGF II in three residues of the C-domain, with serine, isoleucine and asparagine substituted for alanine, valine and serine, respectively, at positions 32, 35 and 36. The final yield of highly purified ovine fetal IGF II was 134 μg, starting from 450 ml of serum.