60 YEARS OF POMC: Purification and biological characterisation of melanotrophins and corticotrophins

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   Figure 1

   A comparison of the primary structures of human and dogfish POMC peptides: ACTH, desacetyl α-MSH and CLIP. Conserved amino acids are emphasized in bold and underlined.
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   Figure 2

   Cation-exchange chromatography of the main MSH-active fractions from a previous gel filtration separation of an extract of 1000 dogfish neurointemediate lobes. The shaded areas represent MSH bioactivity as detected in an in vitro frog skin bioassay (Chadwick & Lowry 1970). (A) Dogfish β-MSH, (B) deamidated dogfish α-MSH, (C) dogfish α-MSH, (D) deamidated dogfish δ-MSH and (E) dogfish δ-MSH. This figure was originally published in the Biochemical Journal (Bennett et al. 1974). Reproduced with permission of The Bioschemical Society.
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   Figure 3

   A comparison of the structures of dogfish and human pro-γ-MSHs and the proposed structure of human big γ-MSH. Conserved amino acids in dogfish pro-γ-MSH are emphasized in bold and underlined. CHO denotes an N-linked carbohydrate moiety.
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   Figure 4

   Tissue-specific processing of POMC in the mammalian pituitary gland and ectopic ACTH-producing tumours. The SH groups show the positions of the cysteine residues in the human joining peptide and the Tyr²²¹–Cys mutation in the β-MSH/β-LPH region reported by Lee et al. (2006).
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   Figure 5

   Gel filtration of an ectopic ACTH tumour extract. Shaded blocks represent MSH bioactivity as detected in an in vitro frog skin bioassay (Chadwick & Lowry 1970); open blocks represent ACTH bioactivity detected in an in vitro rat adrenal cell bioassay (Lowry et al. 1973). The triangles show ACTH immunoreactivity measured using a C-terminally directed ACTH antibody (Ratcliffe et al. 1973). Arrows and ‘A’, ‘C’ and ‘M’ indicate the expected elution positions of ACTH, CLIP and α-MSH, respectively. Reproduced, with permission, from Ratcliffe JG, Scott AP, Bennett HPJ, Lowry PJ, McMartin C, Strong JA & Wallabaum PR (1973) Production of a corticotrophin-like intermediate lobe peptide and of corticotrophin by a bronchial carcinoid tumour, Clinical Endocinology, vol 2, pp51–55. Copyright 1973 John Wiley & Sons.

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