@article{sanders_mcmichael_hendrix_2000, title={Occurrence of Resveratrol in Edible Peanuts}, DOI={10.1021/jf990737b}, abstractNote={Resveratrol has been associated with reduced cardiovascular disease and reduced cancer risk. This phytoalexin has been reported in a number of plant species, including grapes, and may be one of the compounds responsible for the health benefits of red wine. Analytical methods for measuring resveratrol in wine and peanuts were adapted to isolate, identify, and quantify resveratrol in several cultivars of peanuts. Aqueous ethanol (80% v/v) extracts from peanuts without seed coats were purified over alumina/silica gel columns and analyzed by reversed phase HPLC using a C-18 column. Peanuts from each market type, Virginia, runner, and Spanish, produced in four different locations contained from 0.03 to 0.14 microg of resveratrol/g. Seed coats from runner and Virginia types contained approximately 0.65 microg/g of seed coat, which is equivalent to <0.04 microg/seed. Quantitative analysis of 15 cultivars representing 3 peanut market types, which had been cold stored for up to 3 years, indicated a range of 0.02-1.79 microg/g of peanut compared to 0.6-8.0 microg/mL in red wines.}, number={4}, journal={Journal of Agricultural and Food Chemistry}, author={Sanders, Timothy H. and McMichael, Robert W. and Hendrix, Keith W.}, year={2000}, month={Mar} }
 @article{toroser_mcmichael_krause_kurreck_sonnewald_stitt_huber_1999, title={<b>Site‐directed mutagenesis of serine 158 demonstrates its role in spinach leaf sucrose‐phosphate synthase modulation</b>}, DOI={10.1046/j.1365-313X.1999.00389.x}, abstractNote={Summary Site‐directed mutagenesis of spinach sucrose‐phosphate synthase (SPS) was performed to investigate the role of Ser158 in the modulation of spinach leaf SPS. Tobacco plants expressing the spinach wild‐type (WT), S158A, S158T and S157F/S158E SPS transgenes were produced. Expression of transgenes appeared not to reduce expression of the tobacco host SPS. SPS activity in the WT and the S158T SPS transgenics showed light/dark modulation, whereas the S158A and S157F/S158E mutants were not similarly light/dark modulated: the S158A mutant enzyme was not inactivated in the dark, and the S157F/S158E was not activated in the light. The inability to modulate the activity of the S158A mutant enzyme by protein phosphorylation was demonstrated in vitro . The WT spinach enzyme immunopurified from dark transgenic tobacco leaves had a low initial activation state, and could be activated by PP2A and subsequently inactivated by SPS‐kinase plus ATP. Rapid purification of the S158A mutant enzyme from dark leaves of transgenic plants using spinach‐specific monoclonal antibodies yielded enzyme that had a high initial activation state, and pre‐incubation with leaf PP2A or ATP plus SPS‐kinase (the PK III enzyme) caused little modulation of activity. The results demonstrate the regulatory significance of Ser158 as the major site responsible for dark inactivation of spinach SPS in vivo , and indicate that the significance of phosphorylation is the introduction of a negative charge at the Ser158 position.}, number={4}, journal={The Plant Journal}, author={Toroser, Dikran and McMichael, Robert and Krause, Klause‐Peter and Kurreck, Jens and Sonnewald, Uwe and Stitt, Mark and Huber, Steven C.}, year={1999}, month={Feb} }
 @article{sanders_adelsberg_hendrix_mcmichael_1999, title={Effect of Blanching on Peanut Shelf-Life1}, DOI={10.3146/i0095-3679-26-1-3}, abstractNote={Abstract Blanching, seed coat removal, is often a processing step in peanut manufacturing but the general peanut industry consensus is that shelf-life reduction occurs as a result of the process. In order to examine the effects of blanching on shelf-life, runner-type peanuts were blanched using total heating time and final temperature in a 3 × 3 factorial experiment. In each of nine treatments, heating began at 32 C and increased incrementally through six heating zones over a total time of 30,45, or 60 min to a final temperature of either 76.7, 87.8, or 98.9 C. Blanched peanuts from each treatment and nonblanched control samples were stored at 26 ± 1C and ambient RH and were sampled over a 28-wk period. Peroxide value (PV) and oxidative stability index (OSI) of blanched and nonblanched peanuts were similar indicating no meaningful shelf-life differences. Descriptive sensory analysis of peanuts roasted when taken from storage indicated no significant differences in intensity of painty and cardboardy descriptors between blanched and nonblanched peanuts. Mean separations of attributes, including roast peanutty, for which significant differences were noted revealed only a weak, inconsistent relationship between descriptor intensities and final blanching temperature.}, number={1999}, journal={Peanut Science}, author={Sanders, T. H. and Adelsberg, G. D. and Hendrix, K. W. and McMichael, R. W.}, year={1999}, month={Jan} }
 @article{mcmichael_kochansky_klein_huber_1995, title={Characterization of the Substrate Specificity of Sucrose-Phosphate Synthase Protein Kinase}, DOI={10.1006/abbi.1995.1369}, abstractNote={Sucrose-phosphate synthase (SPS; EC 2.4.1.14) is regulated by reversible protein phosphorylation. When the enzyme is phosphorylated it is inactivated and can be reactivated by removal of phosphate. The major regulatory phosphorylation site is known to be Ser158 in the spinach-leaf enzyme, and two protein kinase activities have been resolved chromatographically which phosphorylate SPS at this site in vitro. In this report, we use a set of synthetic peptide substrate analogs based on the phosphorylation site sequence, and a set of Escherichia coli-expressed 26-kDa fragments of spinach SPS which contain the site, to identify the recognition elements that target the two protein kinases to Ser158. The major recognition element consists of basic residues at P-3 and P-6 relative to the phosphorylated serine. Comparison of the spinach enzyme amino-acid sequence with two other plant species show conservation of these amino acids and implies that these signals are also conserved. We also present evidence that glucose-6-phosphate is not only an allosteric activator of SPS but also an inhibitor of SPS-protein kinase per se, thereby allowing it to act at both levels of SPS regulation.}, number={1}, journal={Archives of Biochemistry and Biophysics}, author={Mcmichael, R.W. and Kochansky, J. and Klein, R.R. and Huber, S.C.}, year={1995}, month={Aug} }
 @article{mcmichael_bachmann_huber_1995, title={Spinach Leaf Sucrose-Phosphate Synthase and Nitrate Reductase Are Phosphorylated/Inactivated by Multiple Protein Kinases in Vitro}, DOI={10.1104/pp.108.3.1077}, abstractNote={The regulation of sucrose-phosphate synthase (SPS) and nitrate reductase (NR) activities from mature spinach (Spinacia oleracea L.) leaves share many similarities in vivo and in vitro. Both enzymes are light/dark modulated by processes that involve, at least in part, reversible protein phosphorylation. Experiments using desalted crude extracts show that the ATP-dependent inactivation of spinach SPS and NR is sensitive to inhibition by glucose-6-phosphate. Also, a synthetic peptide homolog of the spinach SPS phosphorylation site inhibits the ATP-dependent inactivation of both enzymes with a similar concentration dependence. We have addressed the possibility that SPS and NR are regulated by the same protein kinase by partially purifying the protein kinases involved. Three unique kinase activities can be separated by anion-exchange and size-exclusion chromatography. Each peak of activity has a different substrate specificity. By gel filtration, they have apparent molecular masses of approximately 45, 60, and 150 kD. Additionally, the activities of the two smaller kinases are dependent on micromolar concentrations of Ca2+, whereas the 150-kD kinase is not. Finally, the 150-kD kinase has a subunit molecular mass of about 65 kD as determined by renaturing the kinase activity in situ following sodium dodecyl sulfate-polyacrylamide gel electrophoresis.}, number={3}, journal={PLANT PHYSIOLOGY}, author={McMichael, R. W., Jr and Bachmann, M. and Huber, S. C.}, year={1995}, month={Jul} }