Open AccessBinding of 13 C-Enriched α-Methyl-D-Glucopyranoside to Concanavalin A as Studied by Carbon Magnetic Resonance
Author(s) -
C. Fred Brewer,
H. Sternlicht,
Donald M. Marcus,
Arthur P. Grollman
Publication year - 1973
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.011
H-Index - 771
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.70.4.1007
Subject(s) - manganese , concanavalin a , chemistry , crystallography , sugar , metal , transition metal , relaxation (psychology) , ion , inorganic chemistry , analytical chemistry (journal) , organic chemistry , biology , biochemistry , neuroscience , in vitro , catalysis
Binding of α-methyl-D-glucopyranoside, uniformly enriched with 14%13 C, to zinc and manganese derivatives of concanavalin A at pH 5.6 was studied by pulsed Fourier transform carbon magnetic resonance techniques. Spin-lattice relaxation (T 1 ) of the [13 C]carbons of the sugar was measured in the absence and presence of the two transition metal derivatives of the protein. In the presence of the manganese derivative of concanavalin A, selective relaxation of the sugar carbons was observed. The values forT 1 reflect different distances between the carbons of the bound sugar and the manganese ion. Calculation of the distance between the manganese ion and each carbon of the sugar permit the 3-dimensional orientation of the bound sugar to be determined relative to the transition metal site in the protein. The results indicate that α-methyl-D-glucopyranoside binds to the protein in the Cl chair conformation with its 3- and 4- carbons closest to the manganese ion at a mean distance of 10 Å.