Analise dos proteoglicanos e proteinas não colagenicas presentes nas cartilagens do tibiotarso e tarsometatarso de frango

AUTOR(ES)
DATA DE PUBLICAÇÃO

1996

RESUMO

The extracellular matriz (ECM) components of different cartilages of mammals is already kwown, but little information is found for ECM of avian cartilage. The purpose of this work was to identi:fy the components of the ECM of tibiotarsal and tarsometatarsal cartilage of chicken. The cartilage was homogeneized in PBS and the fragments extracted with 4M Gu-HCI. The extract was submitted to ultracentrifugation in CsCI gradient, resulting in DI, D2, D3 e D4 fractions. The protein contents was greater in the D4 fraction and in tarsometatarsal extract the concentration of proteins (2,64 mglml) was larger than in tibiotarsal extract (1,6 mglml). With respect to uronic acid, we found more in Dltarsometatarsal (1,51 mg/ml) than in Dl-tibiotarsal (0,80 mg/ml). D4 fraction was dialysed, applied on DEAE-SepOOcel and eluted with 7M urea in 20mM Tris-HCI pH 7,2. Bound material was eluted with a gradient ranging from O to 1,5M NaCI in the same buffer. SDS-P AGE of DEAE fractions of tibiotarsal cartilage, showed a component with 250 kDa, which in presence of 2-Me appears to migrate as a 59 kDa protein. After immunoblotting and CEC/alcian blue, it was demonstrated to be the small proteoglycan fibromodulin in reducing and non-reducing conditions. In tarsometatarsal fractions this protein, migrating as 59 kDa, was detected only in reducing conditions. Another protein migrating as a polidisperse band around 70 kDa was detected in both cartilages. Probably it is the small proteoglycan decorin. Non-collagenous proteins with 46,36 e 30 kDa were detected in both cartilages. DI fration was analysed in Sepharose CL-6B. The cromatography profiles were similar for tibiotarsal and tarsometatarsal cartilages. Both regions showed only one peak tOOt eluted with Kav=0,08. Analysis of fractions in SDS-P AGE and agarose-polyacrilamide gel electrophoresis showed the presence oflarge proteoglycans in tibiotarsal and tarsometatarsal material. The glicosaminoglycans were analysed in agarose gel electrophoresis for each region. The predominant glicosaminoglycan was condroitin sulfate in both cartilages, but its migration in agarose gel was different for tibiotarsal and tarsometatarsal samples. This result was confirmed using chase ABC digestion

ASSUNTO(S)

cartilagem matriz extracelular articulações

ACESSO AO ARTIGO

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