Ymsh

fi-MSH Met-enkephalin (84-101) (104-108)

FIGURE 5-10 Schematic representation of the preproopiomelanocortin molecule formed in pituitary cells, neurons, and other tissues. The numbers in parentheses identify the amino acid sequences in each of the polypeptide fragments. For convenience, the amino acid sequences are numbered from the N-terminus of ACTH and read toward the C-terminal portion of the parent molecule. The locations of Lys-Arg and other pairs of basic amino acid residues are also indicated; these are the sites of proteolytic cleavage in the formation of the smaller fragments of the parent molecule. Abbreviations: AL, anterior lobe; IL, intermediate lobe. Reproduced with permission from Ganong, W. E. (1995). "Review of Medical Physiology," 17th ed., p. 368. Appleton and Lange, Norwalk, CT.

H•Ser-Tyr «Ser*Met - Glu•His-Phe »Arg-Try-Gly•Lys »Pro «Val*Gly-Lys•Lys a-MSH ¡Ser may be acetylated In)

Arg 17

Arg IB

Common to all species-full biological activity

(3-cell tropin

HO-Phe • Glu-Leu • Pro-Phe- Ala-Glu-Ala-Ser-Glu - Asp-Glu-Ala-Gly -Asn 39 35_/\33 30 25

Pro 19 Val 20

Lys 21 Val 22 Tyr- 23

Pro 24

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