Content and properties of different classes of membrane-bound polyribosomes during embryogenesis in chickens
Oborotova, T.A.; Berman, A.E.; Mazurov, V.I.
Biokhimiia 45(3): 554-560
1980
ISSN/ISBN: 0320-9725 PMID: 7378491 Document Number: 156973
The quantitative ratio, chemical composition and sedimentation properties of 3 polyribosomal fractions (free polyribosomes and polyribosomes tightly and loosely bound to the endoplasmic reticulum) isolated from chicken embryos of different age were studied. The fraction of polyribosomes loosely bound to the membranes was obtained from the total preparation of membrane-bound polyribosomes by treatment with high ionic strength solutions. Polyribosomes loosely bound to the membranes and free polyribosomes possess similar chemical composition and sedimentation properties. All the fractions studied were characterized by a much higher polyribosomal content compared to the 80S [Suedberg unit] monomers. During embryogenesis the amount of polyribosomes loosely bound to the membranes decreased; that of tightly bound ones is increased. Apparently, there is an enhanced synthesis of secreted proteins, particularly collagen, on tightly bound polyribosomes during embryogenesis in chicken.