Search

Reduce undesired costs with fresh approaches to vendor-customer relations As the refining industry strives to succeed in a more competitive world, fresh ideas are needed to counter headlines of plant [...]

My compliments to Major McKillip for having the courage--and passion--to respond to my letter ('Ceremonial Excellence', Letters, Volume 11 Issue 10) on the Canadian contingent at Arromanches, on the D-Day [...]

It was with considerable pleasure that I read John P. Maclean's excellent tribute to the 'real' friend to the veterans, in the life of the great soldier, Cliff Chadderton (Volume [...]

With very little evidence yet released by the Department of National Defence (on the case of Capt. Robert Semrau, who is accused of second-degree murder in the death of a [...]

As far as military accuracy in Hollywood films is concerned, I might tell you that a few years ago, I attended a dinner at the RCMI in Toronto, where the [...]

The timing of your article 'The Coffee & Tea Bowls' (Vol. 11 Issue 11) seems appropriate for two reasons: First, it appeared only a few days from the Grey Cup. [...]

Many thanks to Major (ret'd) Stanley Goat for his letter and photos, included in the Posted In column of Volume 11 Issue 7 of Esprit de Corps. The story and [...]

Steady-state radiolysis, pulse radiolysis and epr studies, combined with enzyme activity measurements, were carried out on the mechanism by which radical attack, through one-electron oxidation, inactivates xanthine oxidase. Electron transfer to both the N.3 and Br-2 radical species was used to initiate oxidative damage on the enzyme. Inactivation was found to occur to a greater extent at low than at high pH and is associated with the initial formation of a tryptophanyl radical which converts by a known intramolecular pathway to a tyrosyl radical with a rate constant of 5 × 103 s-1. The tyrosyl radical in turn slowly loses around half of its absorbance at an intramolecular rate constant of 350 s-1 and is consistent with the establishment of a radical equilibrium with cysteine residue(s). The sequence of reactions could be repeated several times on the same irradiated sample implying that restitution of the implied cysteinyl radical occurs leading to other damage in the protein. [image omitted] Epr evidence implies that inactivation of the enzyme from the above sequence of reactions arises in part from alternations to Fe/S center I in the enzyme.