Human beta-melanocyte-stimulating hormone revisited.

Abstract

It is generally accepted that human beta-melanocyte-stimulating hormone (h beta MSH) does not normally exist in humans but was merely an artifactually generated 22-amino acid peptide corresponding to a lipotropin (LPH) fragment (residues 35-56). We examined whether the shorter 18-amino acid peptide h beta MSH-(5-22) could be detected in some human tissues. Normal human pituitaries and hypothalami as well as corticotropin-secreting pituitary and nonpituitary tumors were extracted and chromatographed on Sephadex G-50, and the fractions were measured with two radioimmunoassays using either a COOH-terminal human gamma LPH (h gamma LPH) antiserum that recognized equally h gamma LPH, h beta MSH, and h beta MSH-(5-22) or a mid-portion h gamma LPH antiserum that recognized h gamma LPH and h beta MSH but not h beta MSH-(5-22). Normal pituitaries and pituitary tumors contained a single immunoreactive material coeluting with h gamma LPH. The hypothalami and the nonpituitary tumors all contained h gamma LPH and a smaller molecular weight material that was only detected in the COOH-terminal h gamma LPH radioimmunoassay; its elution volume (Ve/V, 0.75) was identical to that of h beta MSH-(5-22) but different from that of h beta MSH (Ve/V, 0.60); on reversed-phase HPLC, it coeluted with synthetic h beta MSH-(5-22) with a retention time different from that of h beta MSH. It is concluded that h beta MSH-(5-22) that corresponds to the 18-amino acid peptide h beta LPH-(39-56), flanked by two pairs of basic amino acids within the h beta LPH molecule, is a normal maturation product of proopiomelanocortin in human nonpituitary tissues.

• Authors: X Bertagna, F Lenne, D Comar, J F Massias, H Wajcman, V Baudin, J P Luton, F Girard
• Journal: Proceedings of the National Academy of Sciences of the United States of America (Proc Natl Acad Sci U S A) Vol. 83 Issue 24 Pg. 9719-23 (Dec 1986) ISSN: 0027-8424 [Print] United States
• PMID: 2432601 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Epitopes
• Pro-Opiomelanocortin
• Melanocyte-Stimulating Hormones

Topics

• Amino Acid Sequence
• Chromatography, Gel
• Chromatography, High Pressure Liquid
• Epitopes
• Humans
• Hypothalamus (analysis)
• Melanocyte-Stimulating Hormones (analysis, immunology)
• Pituitary Gland (analysis)
• Pro-Opiomelanocortin (metabolism)
• Protein Processing, Post-Translational
• Radioimmunoassay