title: [Quantitative studies of interaction of polyuridylic acid with 30S subunits of ribosomes of Escherichia coli].
abstract: Polyuridilic acid of average molecular weight 18 000 binds to the 30S subunits with stoichiometry 1 : 1 but two kinds of 30S.poly(U) complexes with different stability are formed. The main reason for such heterogeneity was found to be due to the presence or absence of ribosomal protein Sl in 30S subunits. In its presence the association constant of 30S.poly(U) complex is equal 2.7.10(8) M-1, and in the opposite case it is much less 1.5.10(6) M-1. In the same conditions (20 mM MgCl2, 200 mM HN4Cl, 0 degrees) the association constant of binary complex Sl.poly(U) is equal 5.10(7) M-1.
mesh_terms: D004355:Drug Stability; D004926:Escherichia coli / Q000378:metabolism*; D007700:Kinetics; D008970:Molecular Weight; D011072:Poly U / Q000378:metabolism*; D012269:Ribosomal Proteins / Q000378:metabolism; D012270:Ribosomes / Q000378:metabolism*
chemical_list: D012269:Ribosomal Proteins; D011072:Poly U
vernacular_title: Kolichestvennoe izuchenie vzaimodeĭstviia poliuridilivoĭ kisloty s 30S subchastitsami ribosom Escherichia coli.