Cadea alfa das hormonas glicoproteicas

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Subunidade alfa da hCG ou CGA.
Modelo da cadea alfa da hCG modelada sen residuos de carbohidratos.

A cadea alfa das hormonas glicoproteicas ou subunidade alfa das hormonas glicoproteicas é unha proteína que nos seres humanos está codificada polo xene CGA situado no cromosoma 6, a cal está presente en catro hormonas humanas. [1]

As catro hormonas glicoproteicas humanas: gonadotropina coriónica humana (hCG), hormona luteinizante (LH), hormona estimulante dos folículos (FSH), e hormona estimulante da tiroide (TSH) son dímeros que constan dunha subunidade alfa común practicamente idéntica en todas elas [2], e unha subunidade beta diferente, que lles confire a súa especificidade biolóxica. As dúas cadeas están unidas non covalentemente. A proteína alfa codificada por este xene pertence á familia da cadea alfa das hormonas glicoproteicas. [3]

A cadea alfa ten a seguinte secuencia de aminoácidos:

NH2 - Ala - Pro - Asp - Val - Gln - Asp - Cys - Pro - Glu - Cys - Thr - Leu - Gln - Glu - Asn - Pro - Phe - Phe - Ser - Gln - Pro - Gly - Ala - Pro - Ile - Leu - Gln - Cys - Met - Gly - Cys - Cys - Phe - Ser - Arg - Ala - Tyr - Pro - Thr - Pro - Leu - Arg - Ser - Lys - Lys - Thr - Met - Leu - Val - Gln - Lys - Asn - Val - Thr - Ser - Glu - Ser - Thr - Cys - Cys - Val - Ala - Lys - Ser - Tyr - Asn - Arg - Val - Thr - Val - Met - Gly - Gly - Phe - Lys - Val - Glu - Asn - His - Thr - Ala - Cys - His - Cys - Ser - Thr - Cys - Tyr - Tyr - His - Lys - Ser - COOH

As cadeas alfa das catro hormonas denomínanse FSHA, LHA, TSHA e CGA.

Notas[editar | editar a fonte]

  1. Fiddes JC, Goodman HM (Oct 1982). "The gene encoding the common alpha subunit of the four human glycoprotein hormones". J Mol Appl Genet 1 (1): 3–18. PMID 6286817.
  2. UniProt Subunidade alfa das hormonas glicoproteicas
  3. "Entrez Gene: CGA glycoprotein hormones, alpha polypeptide". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1081.

Véxase tamén[editar | editar a fonte]

Outros artigos[editar | editar a fonte]

Outras lecturas[editar | editar a fonte]

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