Alexander R Johnston

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We have used site-directed mutagenesis of amino acids located within the S1 and S2 ligand binding domains of the NR2A N-methyl-D-aspartate (NMDA) receptor subunit to explore the nature of ligand binding. Wild-type or mutated NR1/NR2A NMDA receptors were expressed in Xenopus laevis oocytes and studied using two electrode voltage clamp. We investigated the(More)
NR1/NR2D NMDA receptors display unusually slow deactivation kinetics which may be critical for their role as extrasynaptic receptors. A threonine to alanine point mutation has been inserted at amino acid position 692 of the NR2D subunit (T692A). Recombinant NR1a/NR2D(T692A) NMDA receptors have been expressed in Xenopus laevis oocytes and their(More)
We have examined the function of a conserved serine residue (Ser670) in the S2 ligand-binding region of the NR2A N-methyl-d-aspartate (NMDA) receptor subunit, using recombinant NR1/NR2A receptors expressed in Xenopus laevis oocytes. Mutation of Ser670 to glycine (S670G) in NR2A reduced the potency of glutamate by 124-fold. Single-channel conductance and the(More)
Impaired vision was observed in individual birds from several related flocks of layer breeding chickens. The condition was usually apparent by eight weeks of age. Affected birds were unable to perceive food particles on a flat surface or to negotiate a 50 mm bridge, although apparently able to discern large objects and to respond to bright light. On(More)
Factor V Leiden (F5 L) is a common genetic risk factor for venous thromboembolism (VTE), though it exhibits only 10% penetrance. We conducted a sensitized ENU mutagenesis screen for dominant thrombosuppressor genes based on perinatal lethal thrombosis in mice homozygous for F5 L (F5 L/L) and haploinsufficient for tissue factor pathway inhibitor (Tfpi +/
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