William F Haddon

Learn More
1-Amino-cyclopropane-1-carboxylate synthase (ACS, EC 4.4.1.14) is the key enzyme in the ethylene biosynthetic pathway in plants. The completion of the Arabidopsis genome sequence revealed the presence of twelve putative ACS genes, ACS1-12, dispersed among five chromosomes. ACS1-5 have been previously characterized. However, ACS1 is enzymatically inactive(More)
A sulfated, myotropic neuropeptide termed leucosulfakinin (Glu-Gln-Phe-Glu-Asp-Tyr(SO3H)-Gly-His-Met-Arg-Phe-NH2) was isolated from head extracts of the cockroach Leucophaea maderae. The peptide exhibits sequence homology with the hormonally active portion of the vertebrate hormones human gastrin II and cholecystokinin, suggesting that these peptides are(More)
A sulfated neuropeptide [pGlu-Ser-Asp-Asp-Tyr(SO3H)-Gly-His-Met-Arg-Phe-NH2], with a blocked N-terminus and related to the undecapeptide leucosulfakinin, has been isolated from head extracts of the cockroach, Leucophaea maderae. It exhibits sequence homology with the hormonally-active portion of vertebrate hormones cholecystokinin, human gastrin II and(More)
The sterol composition of two ascomycetous fungi, Saccharomyces cerevisiae and Gibberella fujikuroi, was examined by chromatographic (TLC, GLC, and HPLC) and spectral (MS and 1H-NMR) methods. Of notable importance was that both fungi produced cholesterol and a homologous series of long chain fatty alcohols (C22 to C30). In addition to ergosterol two novel(More)
trans-4-Hydroxy-2-hexenal (t-4HH), a reactive metabolite isolated from the pyrrolizidine alkaloid senecionine, and trans-4-hydroxy-2-nonenal (t-4HN), a product of lipid peroxidation, reacted nonenzymatically with deoxyguanosine at pH 7.4 at 37 degrees C in vitro with each compound yielding two pairs of diastereomeric adducts. Adducts were isolated using(More)
Insect neuropeptides mediate a number of physiological processes critical for insect survival. The numerous neuropeptide sequences that have been reported present an opportunity to decipher the chemical and conformational requirements for neuropeptide-receptor interactions. Chemical and conformational requirements for activity represent a "template" from(More)
The leucosulfakinins (LSKs), isolated from head extracts of the cockroach Leucophaea maderae, are sulfated neuropeptides with homology to gastrin and cholecystokinin. The undecapeptide LSK and decapeptide LSK-II stimulate contractions of the isolated cockroach hindgut. Several structural aspects of the two gastrin/CCK-like insect leucosulfakinins (LSKs) and(More)
The synthesis and biological activity of a bifunctional, heterodimeric insect neuropeptide analog are described. The heterodimer is composed of the C-terminal pentapeptide active core regions of the leucokinin/achetakinin and pyrokinin neuropeptide families linked via their N-terminal amino groups with a succinyl diacid moiety. Members of the(More)
Peanut lots are subject to aflatoxin levels high enough to cause concern to health agencies and trade channels. A possible solution would be to mechanically sort out high aflatoxin nuts from the process stream. Only highly contaminated nuts would need to be removed. However, there exists at present no sorting mechanism which meets commercial needs of(More)