Life Sciences Commons^™

Structural Insights Into The Cl-Par-4 Protein: Ionic Requirements, Conformational Transitions, And Interaction With Cisplatin, Krishna Kumar Raut

Chemistry & Biochemistry Theses & Dissertations

Cancer continues to be the leading global cause of death, with challenges in early diagnosis, drug resistance, non-specific drug targeting, and cancer recurrence and metastasis posing formidable obstacles in cancer therapy. In this context, Prostate Apoptosis Response-4 (Par-4), a pro-apoptotic tumor suppressor protein, emerged as a promising therapeutic target due to its ability to selectively induce apoptosis in cancer cells, thereby minimizing the drug-associated adverse effects. However, a comprehensive understanding of the structural features of Par-4, specifically the caspase-cleaved fragment (cl-Par-4), is crucial for therapeutic advancements.

This dissertation investigated the effects of various ions, both monovalent and divalent, on the …

Biophysical Characterization Of The Par-4 Tumor Suppressor: Evidence Of Structure Outside The Coiled Coil Domain And Interactions With Platinum Chemotherapeutics, Andrea Megan Clark

Chemistry & Biochemistry Theses & Dissertations

Prostate apoptosis response-4 (Par-4) is an apoptosis-inducing tumor suppressor protein. Full-length Par-4 has previously been shown to be a predominantly intrinsically disordered protein (IDP) under neutral conditions, with significant regular secondary structure evident only within the C-terminal coiled coil domain. However, IDPs can gain ordered structure through the process of induced folding, which often occurs under non-neutral conditions. Previous work has shown that the Par-4 leucine zipper, which is a subset of the C-terminal coiled coil domain, is disordered under neutral conditions, but forms a dimeric coiled coil at acidic pH. Increase in ionic strength was also shown to increase …

Characterizing The Activity Of Antimicrobial Peptides Against The Pathogenic Bacterium Clostridium Difficile In An Anaerobic Environment, Adenrele Mojeed Oludiran

Chemistry & Biochemistry Theses & Dissertations

Clostridium difficile is an anaerobic Gram-positive pathogen with high treatment costs and mortality and very high antibiotic tolerance. Antimicrobial host-defense peptides (HDPs) produced naturally by animal immune systems are promising candidates to develop novel therapies for bacterial infection because they cause oxidative stress that damages multiple targets in bacterial cells, so it is difficult for bacteria to evolve resistance to these attacks.

Piscidins, fish-derived HDPs that can also form complexes with copper (Cu) to enhance their activities, are very active against multiple bacterial species in an aerobic environment. We examined their activity against C. difficile and other species in an …

Induction Of Apoptosis In Human Prostate Cancer Cells By Resveratrol, Gary Zulfikar Morris

Chemistry & Biochemistry Theses & Dissertations

Recently attention has been brought to trans-resveratrol's {TR) anticancer activity, as determined through a number of cultured cancer cell models. This activity was attributed to TR behaving as an estrogen, and the orientation of TR' s hydroxyl groups. Based on this work it was of interest to determine whether TR would also be toxic in prostate cancer cells; if toxic, did TR induce necrosis or apoptosis in the cells; was it toxic through hormone mediated pathways; and were TR's hydroxyl groups responsible for its biological activity. To this end, cellular viability was assessed in two different prostate cancer cell …

A Study On The Effects Of The N-Terminal Amino Acid Sequence On The Activation Of Human T-Cell Leukemia Virus Type 1 Protease, Hidayah Muhammad Kendall

Chemistry & Biochemistry Theses & Dissertations

Human T-cell leukemia virus type 1 (HTL V-1) is dependent upon the enzymatic activity of its protease for maturation. Maturation of the protease is facilitated by cleavage of specific amino acid residues, followed by dimerization. The effects of the amino acid sequence located N-terminally to the cleavage site on the ability of the protease to become active were the focus of the current study. These amino acid sequences were contributed by the plasmid vector into which the protease gene was inserted.

Surface probability analyses (SPAs) of the vectors, as well as for native sequences which produce the mature protease and …

Microwell Based Competitive Enzyme Immunoassay For Quantifying Serum Triiodothyronine And Thyroxine Levels, Yiwen Yang

Chemistry & Biochemistry Theses & Dissertations

A microwell based competitive enzyme immunoassay for determination of total thyroxine and triiodothyronine in human serum was developed with use of horseradish peroxidase conjugate. The assay, which can be performed in only 1.5 hours at room temperature, involves simultaneous incubation of T₃- or T₄- HRPO conjugate and serum sample in anti-T₃ or anti-T₄ gamma globulin fraction coated polystyrene microwells.

Isolation of anti-T₃ and anti-T₄ gamma globulin fractions were accomplished from whole antiserum by using DEAE-cellulose chromatograph. A carbodiimide coupling method was described to prepare the T₄- and T₃-HRPO …

Hypoxanthine-Induced Differentiation Of Cultured Human Leukemia Cells, Gayle Jennette Singleton

Chemistry & Biochemistry Theses & Dissertations

Human cultured leukemia cells appear to have a decreased amount of inosine in their tRNA. When cells with inosine deficient tRNA are placed in a hypoxanthine fortified media, they incorporate hypoxanthine into their tRNA by the action of the enzyme tRNA-hypoxanthine ribosyl transferase. This generates the nucleoside inosine in the tRNA. The cultured human leukemia cell lines, CCRF-CEM, HL-60, and HGPRT(-) HL- 60, incorporate hypoxanthine into their tRNA, as determined by tRNA isolation, hydrolysis, and HPLC analysis. Hypoxanthine treatment dramatically inhibited cell growth in conjunction with partial induction of differentiation in the CCRF-CEM, HL-60, and HGPRT ( - ) HL-60 …

The Effects Of Tri-O-Cresyl Phosphate On 2',3'-Cyclicnucleotide-3'-Phosphohydrolase Activity In Neural And Non-Neural Tissue Of The Rat, Mark K. Schlager

Chemistry & Biochemistry Theses & Dissertations

A total of 44 Long-Evans rats received 5.7 g/kg tri-O-cresyl phosphate (TOCP) orally every 3 days for 6 days. A second group of 13 rats received 4.6 g/kg orally every 3 days for 6 days. Animals were administered atropine sulfate (10 mg/kg) intraperitoneally every 6 hours or as needed to alleviate cholinergic symptoms. Ten control animals were given corn oil orally. Eight rats (18%) survived the 5.7 g/kg dose regimen and 5 rats (38%) survived the 4.6 g/kg dose regimen. Surviving rats were killed at 30-33 days post-dose. Signs of delayed neuropathy included ataxia and motor impairment.

The CNP activity …

The Analysis Of S-Adenosylmethionine And S-Adenosylhomocysteine In Normal And Neoplastic Cells, Kathryn Elizabeth Godburn

Chemistry & Biochemistry Theses & Dissertations

Altered patterns of methylation have been shown in both ribosomal and transfer RNA isolated from cancer cells. In contrast to the elevated activity of the methyltransferases responsible for this modification, hypomethylation appears as a general characteristic. The endogenous levels of S-adenosylmethionine and S-adenosylhomocysteine are important in relationship to their role as substrate and product of the transmethylation reaction. The levels of S-adenosylmethionine and S-adenosylhomocysteine were determined using phosphocellulose cation exchange or high pressure liquid chromatography. High voltage paper electrophoresis was used in a modified procedure to directly resolve (³⁵s) labeled S-adenosylmethionine and S-adenosylhomocysteine in small quantities of cell …

The Synthesis And Evaluation Of The Potential Antineoplastic Activity Of The Semicarbazone And The Thiosemicarbazone Derivatives Of The Di-2-Pyridyl Ketone And The 1,8-Diazafluorenone Ring Systems, Adriene Y. Principe

Chemistry & Biochemistry Theses & Dissertations

A number of' a-(N)-heterocyclic thiosemicarbazones have been synthesized and evaluated for potential antineoplastic activity since Brockman and colleagues2 reported the antineoplastic activity of' 2-f'ormylpyridine thiosemicarbazone (1). The primary objective of' this research project has been the synthesis and characterization of' the semicarbazone and the thiosemicarbazone derivatives of' the di-2-pyridyl ketone, (9-a) and (9-b), and the 1,8-diazaf'luorenone, (10-a) and (10-b), ring systems, as well as the evaluation of' these compounds for both in vitro and in vivo antineoplastic activity against Ehrlich ascites tumor cells in mice. These studies have suggested that di-2-pyridyl ketone thiosemicarbazone (9-b) is as effective as 2-formylpyridine …