@article{kaufman_hentsch_baumbach_buettner_dadd_huang_hammond_carbonell_2002, title={Affinity purification of fibrinogen using a ligand from a peptide library}, volume={77}, ISSN={["0006-3592"]}, DOI={10.1002/bit.10120}, abstractNote={An affinity resin containing the peptide ligand Phe-Leu-Leu-Val-Pro-Leu (FLLVPL) has been developed for the purification of fibrinogen. The ligand was identified by screening a solid-phase combinatorial peptide library using an immunostaining technique. The specific binding of fibrinogen to the ligand has been characterized by isothermal calorimetry and adsorption isotherms and is dominated by both hydrophobic interactions and ionic interactions with the N-terminal free amino group. The effective association constant of fibrinogen was substantially higher when the peptide was immobilized on the resin than in solution; moreover, it increased with increasing peptide density, suggesting a cooperative binding effect. A low ionic strength buffer at pH 4 was used successfully to elute adsorbed fibrinogen from the column with high purity, retention of factor XIII crosslinking activity, and minimal, if any, loss of biological function. This general approach to ligand selection and characterization can be used to develop peptide ligands for the affinity purification of diverse proteins on a large scale.}, number={3}, journal={BIOTECHNOLOGY AND BIOENGINEERING}, author={Kaufman, DB and Hentsch, ME and Baumbach, GA and Buettner, JA and Dadd, CA and Huang, PY and Hammond, DJ and Carbonell, RG}, year={2002}, month={Feb}, pages={278–289} } @article{stoskopf_paul-murphy_kennedy-stoskopf_kaufman_2001, title={American College of Zoological Medicine recommendations on veterinary curricula}, volume={219}, ISSN={["0003-1488"]}, DOI={10.2460/javma.2001.219.1532}, number={11}, journal={JOURNAL OF THE AMERICAN VETERINARY MEDICAL ASSOCIATION}, author={Stoskopf, MK and Paul-Murphy, J and Kennedy-Stoskopf, S and Kaufman, G}, year={2001}, month={Dec}, pages={1532–1535} } @article{kaufman_felder_fuller_2000, title={Accounting for individual effort in cooperative learning teams}, volume={89}, DOI={10.1002/j.2168-9830.2000.tb00507.x}, abstractNote={An “autorating” (peer rating) system designed to account for individual performance in team projects was used in two sophomore‐level chemical engineering courses in which the students did their homework in cooperative learning teams. Team members confidentially rated how well they and each of their teammates fulfilled their responsibilities, the ratings were converted to individual weighting factors, and individual project grades were computed as the product of the team project grade and the weighting factor. Correlations were computed between ratings and grades, self‐ratings and ratings from teammates, and ratings received and given by men and women and by ethnic minorities and non‐minorities. Incidences of “hitchhikers” (students whose performance was considered less than satisfactory by their teammates), “tutors” (students who received top ratings from all of their teammates), dysfunctional teams, and teams agreeing on a common rating were also determined. The results suggest that the autorating system works exceptionally well as a rule, and the benefits it provides more than compensate for the relatively infrequent problems that may occur in its use.}, number={2}, journal={Journal of Engineering Education}, author={Kaufman, D. B. and Felder, R. M. and Fuller, H.}, year={2000}, pages={133–140} } @article{kaufman_hayes_buettner_hammond_carbonell_2000, title={Chromatographic resolution of tryptophan enantiomers with L-Leu-L-Leu-L-Leu peptide - Effects of mobile phase composition and chromatographic support}, volume={874}, ISSN={["0021-9673"]}, DOI={10.1016/S0021-9673(99)01299-6}, abstractNote={Tryptophan enantiomers have been separated by zwitterion pair chromatography using L-leucine-L-leucine-L-leucine peptide as the zwitterion pairing agent. The peptide ligand is adsorbed onto an octadecylsilane support with excess ligand present in bulk solution. This article examines the roles of the hydrophobic matrix and the mobile phase components on tryptophan enantiomer binding and resolution. Capacity factors and enantioselectivites are given for both hydrophobic and hydrophilic matrices using mobile phases containing Leu-Leu-Leu peptide and/or salt. A decrease in selectivity upon the addition of mobile phase salt suggests that quadrupolar ion-pairing contributes to chiral recognition. Results indicate that binding is significantly reduced and separation is not achieved when Leu-Leu-Leu is coupled onto cross-linked or polymerized hydrophilic resins as well as onto macroporous polystyrene resin. However, resin-immobilized Leu-Leu-Asp-Leu-Leu-Leu, Leu-Leu-Glu-Leu-Leu-Leu, and Leu-Leu-Leu-Glu-Leu-Leu peptides, with ion-pairing sites designed to mimic the Leu-Leu-Leu-saturated C18 support, also do not resolve tryptophan enantiomers. This suggests the Leu-Leu-Leu structure is critical for enantiomer resolution. Because D- and L-tryptophan are separated in the absence of bulk Leu-Leu-Leu, chiral discrimination is believed to occur at the surface of the octadecylsilane support.}, number={1}, journal={JOURNAL OF CHROMATOGRAPHY A}, author={Kaufman, DB and Hayes, T and Buettner, J and Hammond, DJ and Carbonell, RG}, year={2000}, month={Mar}, pages={21–26} } @inproceedings{kaufman_felder_fuller_1999, title={Peer ratings in cooperative learning teams}, booktitle={1999 ASEE Annual Conference Proceedings, ASEE, June 1999}, publisher={Washington, D.C.: American Society for Engineering Education}, author={Kaufman, D. B. and Felder, R. M. and Fuller, H.}, year={1999} } @article{mondorf_kaufman_carbonell_1998, title={Screening of combinatorial peptide libraries: Identification of ligands for affinity purification of proteins using a radiological approach}, volume={52}, DOI={10.1111/j.1399-3011.1998.tb01257.x}, abstractNote={Peptides deduced from peptide libraries may serve as affinity ligands for protein purification. Identification of a ligand that binds the protein of interest depends highly on the screening method used. One approach which offers simple and direct detection involves screening a solid-phase peptide library against a radiolabeled target protein. We have developed a radiological screening method, using 14C as a radioactive label, that offers high resolution and sensitivity. Less than 100 DPM/bead are detectable after a one-day exposure using autoradiography. The validity of the technique was illustrated by screening a solid-phase hexameric-peptide library spiked with YNFEVL-beads against 14C-labeled ribonuclease S-protein. For this particular system, the amount of protein bound to a single bead was estimated to be in the femtomolar range with a peptide:protein ratio of 500:1. Finally, a portion of the library was screened against 14C-labeled fibrinogen. Three peptides deduced from the library, WQEHYN, WQETYQ, and YENYGY, purified fibrinogen from a mixture with albumin.}, number={6}, journal={Journal of Peptide Research}, author={Mondorf, K. and Kaufman, D. B. and Carbonell, R. G.}, year={1998}, pages={526–536} }