Isolation and Characterization of Collagen - Synthesizing Polysomes from Chick Embryos |
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| Authors: | Wang L Andrade H J Jr Silva S M F Sim[otilde]es C L Ďabronzo F H R Brentani |
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| Institution: | 1. Laboratóries de Oncologia Experimental, Faculdade de Iledicina , Universidade de Sao Paulo , Caixa Postal, 2921, Séo Paulo, Brasil;2. Undergraduate fellows of the Funda??o de Araparo à. Pesquisa do Estado de S?o Paulo;3. Departamento de Bioquíraica , Instituio de Química, Universidade de S?o Paulo |
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| Abstract: | Collagen - synthesizing polysomes were isolated by low-speed oentrifugation of the post-mitochomirial supernatant of chick homogenates. Electron microscopy of the fraction thus isolated shows it to be exclusively composed of ribosomes. Amino acid incorporation in vitro showed that these particles were efficient in the incorporation of proline, but not tryptophan, as opposed to ribosomes obtained from the supernatant of the low-speed oentrifugation. The incorporation process was highly dependent on GTP, and exibited an optimal Mg2+ concentration of 5.6 mN. The reaction was inhibited by RNase, elongation inhibitors as anysomycin, sparsomycin, fusidic acid and GDPCP. It was also moderately inhibited by initiation inhibitors such as aurintricarboxilic acid and pyrocatechol violet. The product of the incorporation was characterized as collagen by its sensitivity towards purified collagenase, lack of tryptophan, chromatography in CN-cellulose and molecular sieve chromatography in Sephadex G-200. |
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| Keywords: | Thymopentin Amino acids Nucleophile Thymopoietin |
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