Can I read Arg-242 is necessary for allosteric coupling of cyclic AMP-binding sites A and B of RI subunit of cyclic AMP-dependent protein kinase. on EtoBox?

Arg-242 is necessary for allosteric coupling of cyclic AMP-binding sites A and B of RI subunit of cyclic AMP-dependent protein kinase. by M.M. Symcox; R.D. Cauthron; D. Ogreid; R.A. Steinberg is a Biochemistry, Genetics and Molecular Biology article available to read on EtoBox.

What is Arg-242 is necessary for allosteric coupling of cyclic AMP-binding sites A and B of RI subunit of cyclic AMP-dependent protein kinase. about?

## The functional consequences of Arg-242 to Ser or Lys substitutions in type Ia regulatory (R) subunits of CAMP-dependent protein kinase were analyzed by using recombinant murine R subunits expressed in Escherichia coli. These mutations arose in CAMP-resistant mutants to S49 mouse lymphoma cells and were shown previously to inhibit CAMP binding to site A, the more amino-terminal of two intrachain cAMF"binding sites. ## Binding of CAMP to site A of the mutant R subunits could be detected by CAMP-dependent quenching of endogenous tryptophan fluorescence, ['HICAMP binding to mutant R subunits with the Arg-242 mutations without or with an inactivating mutation in site B, or biphasic dissociation of ['HICAMP from the mutant subunits at low temperature. The mutations reduced site A affinities by about 26-fold, and the reductions were attributable to accelerated rates of CAMP dissociation. While the presence of CAMP in site A retards dissociation of ['HICAMP from site B of wild-type R subunits, saturation of site A had little or no effect on dissociation of [SH]cAMP from site B of the mutant subunits. The predominant effect of the mutations, therefore, was loss of allosteric coupling bet

Who reads Arg-242 is necessary for allosteric coupling of cyclic AMP-binding sites A and B of RI subunit of cyclic AMP-dependent protein kinase.?

Author

M.M. Symcox; R.D. Cauthron; D. Ogreid; R.A. Steinberg

Publisher

Elsevier BV

Published

1994

Language

EN

Field

Biochemistry, Genetics and Molecular Biology (Life Sciences)