Cadea alfa das hormonas glicoproteicas

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

↑ Fiddes JC, Goodman HM (1982). "The gene encoding the common alpha subunit of the four human glycoprotein hormones". J Mol Appl Genet 1 (1): 3–18. PMID 6286817.
↑ UniProt Subunidade alfa das hormonas glicoproteicas
↑ "Entrez Gene: CGA glycoprotein hormones, alpha polypeptide".

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Bibliografía

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[pmid6286817-1] Fiddes JC, Goodman HM (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".

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