Rex E. Shepherd

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Esr and electronic spectra of complexes of the general composition VO(AA)2 and VO(ox)(AA) have been characterized; AA = gly, his, cys, pro, val, met, asp amino acids. Spectra of the formulation VO(ox)(LL) (with LL = imidazole plus monodentate oxalate, histamine plus monodentate oxalate, histidine, cysteine, 4-imidazolepropionic acid, mercaptopropionic acid,(More)
Affinity tags are often used to accomplish recombinant protein purification using immobilized metal affinity chromatography. Success of the tag depends on the chelated metal used and the elution profile of the host cell proteins. Zn(II)-iminodiacetic acid (Zn(II)-IDA) may prove to be superior to either immobilized copper or nickel as a result of its(More)
[Pd(II)(mida)(peptide)] complexes for the series of peptides of sequence X(1)-His-X(3)-His-His were studied by molecular mechanics methods using Spartan, MMFF94, and SYBYL programs with X(1) = X(3) = glycine (G), phenylalanine (F), tyrosine (Y), tryptophan (W), and with X(1) = glycine (G) and X(3) = proline (P). For comparison purposes, data were also(More)
The coordination of peptides Ser-Pro-His-His-Gly-Gly (SPHHGG) and (His)6 (HHHHHH) to [PdII(mida)(D2O)] (mida2- = N-methyliminodiacetate) was studied by 1H NMR as model reactions for CuII(iminodiacetate)-immobilized metal affinity chromatography (IMAC) sites. This is the first direct physical description of peptide coordination for IMAC. A three-site(More)
Lactobionic acid, a major constituent of a solution used to preserve organs prior to transplantation, can chelate ferric iron. This is evident by its ability to solubilize iron as well as changes that occur in the UV-VIS spectra of iron in its presence. Relative to iron (III) chelated to EDTA, the lactobionic acid-iron (III) complex is less able to(More)
Delivery agents which can carry the {Ru(NO)}(6) chromophore ("caged NO") are desired for vasodilation and for photodynamic therapy of tumors. Toward these goals, complexes derived from [RuCl(3)(NO)(H(2)O)(2)]= (1) have been prepared using dipyridylamine (dpaH) as mono and bis adducts, [Ru(NO)Cl(3)(dpaH)] = (2) and [Ru(NO)Cl(dpaH)(2)]Cl(2) = (3). The dpaH(More)
A single ip inoculation of female, outbred Sprague-Dawley rats with a viable mouse xenotropic type C virus significantly reduced the incidence and/or retarded the development of mammary carcinoma induced by 7, 12-dimethylbenz[a]anthracene administered orally 7 days after virus. Although infectious virus could not be isolated from organs of infected rats,(More)