Radioimmunoassay of relaxin-like gonad-stimulating peptide in the starfish Patiria (=Asterina) pectinifera.
Gen Comp Endocrinol
; 243: 84-88, 2017 03 01.
Article
en En
| MEDLINE
| ID: mdl-27838378
ABSTRACT
A relaxin-like gonad-stimulating peptide (RGP) from starfish Patiria (=Asterina) pectinifera is the first identified invertebrate gonadotropin for final gamete maturation. An antiserum against P. pectinifera RGP (PpeRGP) was produced by immunizing rabbits with a PpeRGP sulfanyl-polyethylene glycol derivative conjugated with keyhole limpet hemocyanin (KLH) as the antigen. The antiserum was used for the development of a specific and sensitive radioimmunoassay (RIA) for the measurement of RGP. In binding experiments using radioiodinated PpeRGP and antiserum against PpeRGP, a displacement curve was obtained using radioinert PpeRGP. The sensitivity of the RIA, defined as the amount of PpeRGP that significantly decreased the counts by 2 SD from the 100% bound point, averaged 0.040±0.002pmol PpeRGP per 100µl assay buffer (0.40±0.02nM) in 10 assays. Intra-assay and inter-assay coefficients of variation were 6.1% and 2.7%, respectively. Serial dilution of whole homogenates from the radial nerve cords and circumoral nerve-rings of P. pectinifera produced displacement curves parallel to the PpeRGP standard. Thus, the amounts of PpeRGP were determined as 1.54±0.09pmol/mg wet weight of radial nerves and 0.87±0.04pmol/mg wet weight of nerve-rings, respectively. On contrary, pyloric stomach, pyloric caeca, tube-feet, ovaries, testes, and ovarian follicle cells did not react in the RIA system. Furthermore, the A- and B-chains of PpeRGP, Asterias amurensis RGP, bovine insulin, and human relaxin did not show cross-reactivity in the RIA. These results strongly suggest that the RIA system is a highly specific and sensitive with respect to PpeRGP.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Fragmentos de Péptidos
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Relaxina
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Radioinmunoensayo
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Asterina
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Gónadas
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Hormonas de Invertebrados
Límite:
Animals
Idioma:
En
Revista:
Gen Comp Endocrinol
Año:
2017
Tipo del documento:
Article
País de afiliación:
Japón