Biochemistry Commons^™

Polymer Microchips For Capillary Electrophoresis And Electric Field Gradient Focusing Of Biomolecules, Ryan Thomas Kelly

Theses and Dissertations

Polymeric materials have seen increasing use as microfluidic device substrates due to their low cost and the simplicity of templated fabrication procedures. I showed that poly(methyl methacrylate) (PMMA) microdevices could be enclosed in a boiling water bath, which allowed the seal to form more quickly than in conventional approaches, and enabled microchannels to remain hydrated throughout the bonding process. Microchip capillary electrophoresis (µ-CE) devices were fabricated using water-based enclosure, and a mixture of fluorescently labeled amino acids was separated in 30 s in these microchips. To create more robust capillary electrophoresis (CE) microdevices with improved separation performance, phase-changing sacrificial materials …

The Carboxyl Terminus Of The Bacteriophage T4 Dna Polymerase Is Required For Holoenzyme Complex Formation, Anthony J. Berdis, Patrice Soumillion, Stephen J. Benkovic

Chemistry Faculty Publications

To further elucidate the mechanism and dynamics of bacteriophage T4 holoenzyme formation, a mutant polymerase in which the last six carboxyl-terminal amino acids are deleted, was constructed, overexpressed, and purified to homogeneity. The mutant polymerase, designated ΔC6 exo−, is identical to wild-type exo− polymerase with respect to kcat, kpol, and dissociation constants for nucleotide and DNA substrate. However, unlike wild-type exo− polymerase, the ΔC6 exo− polymerase is unable to interact with the 45 protein to form the stable holoenzyme. A synthetic polypeptide corresponding to the carboxyl terminus of the wild-type exo− polymerase was tested as an in vitro inhibitor of …

Purification And Characterization Of The Prostate Cancer-Associated Antigen: 7e11-C5, Qi Feng

Theses and Dissertations in Biomedical Sciences

A murine monoclonal antibody (MAb), 7E11-C5, recognizes a prostate organ-specific antigen. Under reducing conditions, the 7E11-C5 antigen exhibited major 100-Kd and minor 70-Kd bands, suggesting that the antigen comprises two peptide chains. The antigen was detected in pooled normal human seminal plasma, xenograft tissue extract of a prostate adenocarcinoma cell line, LNCaP, and tissue extracts of benign prostatic hyperplasia (BPH) and prostate carcinomas, but was not identified in any of the non-prostate tissue extracts tested. Antibodies of the three major prostate-associated antigens (prostatic acid phosphatase (PAP), prostate specific antigen (PSA) and prostate secretory protein (PSP)) were unable to block the …

The Role Of Small Peptides In Cancer Physiology And Chemotherapy, Bao-Ling Tsay

Theses and Dissertations in Biomedical Sciences

The targeting of proven anticancer drugs specifically to cancer cells would provide a unique opportunity to restrict neoplasms without damaging the cancer patient. The present research utilizes the phenomenon of illicit transport, i.e. the coupling of normally impermeant metabolites to permeant metabolites, in targeting the drug melphalan to mouse Ehrlich ascites tumor cells. The dipeptide beta-alanyl-melphalan was synthesized and tested in vitro for toxicity towards mouse Ehrlich ascites tumor cells, mouse liver cells, and mouse 3T3 embryonic cells. The parent compound, melphalan, was used as a control treatment. In addition, both melphalan and beta-alanyl-melphalan were utilized in in vivo chemotherapeutic …

Modification Of Chromium(Vi)-Induced Dna Damage By Glutathione And Cytochromes P-450 In Chicken Embryo Hepatocytes., Doreen Y. Cupo, Karen E. Wetterhahn

Dartmouth Scholarship

The role of glutathione and cytochrome P-450 in the production of DNA damage by chromium(VI) was examined in chicken embryo hepatocytes by the alkaline elution technique. Cellular levels of glutathione and cytochrome P-450 were altered by treating the hepatocytes with N-acetyl-L-cysteine, buthionine sulfoximine, isopentanol, or beta-naphthoflavone. A dramatic increase in chromium(VI)-induced DNA strand breaks was observed after increasing glutathione levels in the cells. Chromium(VI)-induced DNA strand breaks were even more numerous when the level of cytochrome P-450 was also increased. Upon depletion of glutathione levels and induction of cytochrome P-450 or cytochrome P-448, little or no DNA strand breaks or …

Evaluation Of Peptide Assimilation In Ehrlich Ascites Tumor Cells, John M. Castellano

Biological Sciences Theses & Dissertations

The dipeptides glycyl-L-(³H)-leucine and L-phenylalanyl-L-(³H)-leucine were synthesized in radioactive form and utilized in the analysis of peptide transport and hydrolysis by Ehrlich ascites tumor cells. The tumor cells were cultured in the abdominal cavity of CF-1 albino mice and harvested into sterile isotonic buffer for all experimental analyses.

The results of this study reveal that the tumor cells rapidly accumulate radiolabel when incubated with the above mentioned peptides, but that the peptide is most probably hydrolyzed extracellularly and free L-(³)-leucine transported. This hypothesis is based on the observations of reduction in accumulation of radiolabel …