Life Sciences Commons^™

Investigating Bzip Recognition Of Dna Sequences Through A Knob-Socket Perspective, Aaron Tran

University of the Pacific Theses and Dissertations

To investigate whether higher order packing interactions confer protein-DNA specificity, a modified Knob-Socket (KS) model was used to analyze the interface of bZIP-DNA crystal structures. The KS analysis identified a nine-residue quadripartite recognition core consisting of four contiguous KS pockets P1, P2, N3, and N4 that each pack one of the four DNA half-site bases in the target sequence. Only one base per base pair packs, and these interactions are split across the DNA strands: the first two positive strand positions 1p and 2p pack into P1 and P2 while the last two negative strand positions 3n and 4n pack …

Optimizing The Human Aryl Hydrocarbon Receptor (Hahr) Expression In Pichia Pastoris, Junyu Qian

University of the Pacific Theses and Dissertations

The aryl hydrocarbon receptor (AHR) is a transcription factor which heterodimerizes with the aryl hydrocarbon receptor nuclear translocator (Arnt) to regulate downstream gene transcription. For the purpose of studying the crystal structure of human aryl hydrocarbon receptor (hAHR), it is essential to obtain abundant amount of pure recombinant protein.Basing on the benefits of using P. pastoris system to produce recombinant protein, including appropriate folding, secretion of interest proteins to the external environment of the cell, and easier purification process of protein due to the its limited production of endogenous secretory proteins [1], our lab chose P. pastoris yeast as the …

Post-Translational Modification And Degradation Mechanisms Of The Aryl Hydrocarbon Receptor, Yujie Yang

University of the Pacific Theses and Dissertations

The aryl hydrocarbon receptor (AHR) is a transcription factor first discovered to be activated by exogenous ligands, such as dioxins, and helps promote downstream gene (e.g. CYP1A1) transcription to metabolize the toxicants. With the reports of various AHR targets genes, the expression levels and activities of AHR have been implicated in many physiological and pathological situations. Understanding how AHR protein level is regulated would provide more information to target AHR. AHR stays in the cytosol in the absence of ligand in a complex with HSP90, p23 and XAP2. After ligand activation, AHR translocates into the nucleus, fulfilling its transactivation function …

Development Of Linked-Domain Protein Inhibitors Of The E2-Conjugating Enzyme Ube2d, Anneroos E. Nederstigt

University of the Pacific Theses and Dissertations

In most eukaryotic organisms, the ubiquitination pathway is one of the most important and versatile signaling systems in use. It is integral to processes such as protein degradation and homeostasis, DNA repair cell cycle regulation, signaling and regulation, epigenetics, and many more. Ubiquitin (Ub) is a short polypeptide of 8.6 kDa, 76 residues that functions as a reversible post-translation modification (PTM). It furthermore contains 7 different lysine residues (K6, K11, K27, K29, K33, K48, K63), all of which can form isopeptide linkages with one another to link individual Ub moieties to form unique polyUb chains onto substrates. The type of …

Investigating The Effect Of Rutaecarpine On The Benzo[A]Pyrene-Induced Dna Damage In Vitro, You Li

University of the Pacific Theses and Dissertations

Benzo[a]pyrene (BaP), is one of the most potent mutagens and carcinogens known. It requires metabolic activation through cytochrome P450 (CYP)1A1 to yield the ultimate carcinogenic metabolite, benzo[a]pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE). BPDE can bind to DNA and form predominantly covalent (+) trans adducts at the N2 position of guanine causing DNA damage. Rutaecarpine (RTC) is an herbal medicine that has been used to treat several diseases such as headache, hypertension, gastrointestinal disorders, amenorrhea, and anti-inflammation. It has also been reported as a potent inducer of CYP enzymes, including CYP1A1, and CYP1A2. The mechanisms underlying up-regulation of CYP1A1 by RTC is dependent on aryl …

Design And In Vitro Characterization Of Lipids With A Ph-Sensitive Conformational Switch And Their Liposomes For Anticancer Drug Delivery, Shen Zhao

University of the Pacific Theses and Dissertations

The traditional anticancer drugs are distributed in vivo through systemic blood circulation with a very small portion reaching the tumor site. Targeted drug delivery systems are developed in efforts to concentrate the drug molecules in the tissue of interest while reducing the drug distribution to healthy tissues to reduce the side effects. Liposomes are colloidal systems composed of amphiphilic molecules that assemble into vesicle structures in aqueous media. They are common carriers for targeted drug delivery with the advantages of low toxicity, low immunogenicity and the ability of encapsulating both lipophilic and hydrophilic drugs.

Prior research indicated the advantages of …

Influence Of The Estrous Cycle And Female Sex Hormones On Ghb Toxicokinetics, Hao Wei

University of the Pacific Theses and Dissertations

Gamma-Hydroxybutyrate (GHB) is an endogenous short-chain fatty acid formed from Gamma-aminobutyric acid (GABA). Clinically, GHB is marketed in the United States as Xyrem to treat narcolepsy with cataplexy and in Europe for the treatment of alcohol withdrawal and narcolepsy. However, the illicit use and abuse of GHB occurs due to its sedative/hypnotic and euphoric effects. Monocarboxylate transporters (MCTs and SMCTs) are integral membrane proteins that control the bidirectional transport of endogenous substrates including lactate, acetate and pyruvate. They have also been found to transport and mediate the clearance and distribution of GHB. MCTs demonstrate a wide tissue distribution, including brain, …

Peptide-Drug Conjugate For Her2-Targeted Drug Delivery, Yan Wang

University of the Pacific Theses and Dissertations

Recent strategies for anticancer drug design have been focused on utilizing antibody as a drug or targeted moiety for targeted drug delivery. Antibody−drug conjugates (ADCs) have become a promising new class of targeted therapeutic agents for treatment of cancer. ADCs are designed to preferentially direct a cytotoxic drug to a cell-surface antigen recognized by an antibody. However, there are some challenges in developing ADCs, such as limited solid tumor penetration, high manufacturing costs and antibody-drug stoichiometry. Smaller molecules such as peptides have been shown to specifically bind to cancer related targets. These peptides can be used to form peptide-drug conjugates …

Investigations On Cancer Cell Biological Effects Of Cdk8 Inhibitor Q-12, Zhixin Lu

University of the Pacific Theses and Dissertations

Over the past two decades, protein kinases have been intensively investigated as targets to treat neoplastic diseases. Many protein kinase inhibitors not only have therapeutic potential but are becoming invaluable reagents for the study of cell signaling.

We aspired to use our Cyclin-Dependent Kinase 8 inhibitor, Q-12, as a probe for biomarker discovery for CDK8 inhibitor sensitive tumor types. Q-12 shows potent inhibition of cell viability and induction of apoptosis process in some triple-negative breast cancer and colorectal cancer cell lines in vitro. Western blot results indicate that the reduction of STAT1 phosphorylation could be a robust indicator of CDK8 …

Determining The Role Played By Aryl Hydrocarbon Receptor (Ahr) In The Colon Carcinoma Tumor Model, Poonam Yakkundi

University of the Pacific Theses and Dissertations

Aryl hydrocarbon receptor (AHR), commonly known as an environmental sensor involved in the metabolism and elimination of xenobiotic substances, is also an important modulator in the development and functioning of the immune system. AHR expression is varied in the T cell subsets with the highest expression in T-helper 17 and T regulatory cells. Work from many researchers has suggested that AHR can act as a tumor promoter or a tumor suppressor depending on the tumor type. Our goal is to understand the role played by AHR in MC38 syngeneic colon carcinoma tumor model. In the absence of AHR, MC38 tumor …

Optimization Of Porcine Buccal Mucosa For In Vitro Evaluation, Upendra D. Kulkarni

University of the Pacific Theses and Dissertations

Porcine buccal mucosa has been extensively used as in vitro model to study the permeability of drugs and assess their potential to deliver through buccal route. Porcine buccal mucosa is found to be very similar to human oral mucosa in structure and function. However, the in vitro permeation studies across porcine buccal mucosa show high variability which is mostly due to the various experimental and biological variables that are often overlooked while conducting such studies.

The precise nature of the permeability barrier offered by the various tissue layers of buccal mucosa was investigated in this study. It was observed that …

The Partial Purification And Characterization Of A Soluble Activator For The Sodium Adenosinetriphosphatase From Rat Cerebral Cortex And The Effect Of Cholinergic Agents, Thibaldo Javier Manrique Blanco

University of the Pacific Theses and Dissertations

In order for organisms to co-exist with nonliving matter, envelop to protect their delicate internal functions must be present. There are other reasons for this boundary to exist, e.g. to limit the volume occupied by the organism and to compartmentalize the contents of the organism so that certain critical concentrations may be easily maintained. Such envelopes are, of course, the cellular membranes. Membranes differ greatly between species, as well as within species. Given the complexity to which organisms have evolved, membranes have developed with a myriad of functions and components. It is easy to see differences between plant cellular membranes …

Pharmacognosy Of The Saururaceae : Microscopy Of Powdered Drugs, Prakash Vaman Mallya

University of the Pacific Theses and Dissertations

Plants of the family Sauruaceae are used in folk medicine in various parts of the world. Chemistry of some plants of this family and their chemotaxonomy has been investigated in our laboratory (12).

It is very difficult to establish identity and authenticity of commercially available crude drugs and powders of the Saururaceae because a detailed, collective study of microscopic features of these plants is not available. Original papers establishing plants of this family (see later) do not include microscopic features; they describe only gross morphologic and other classical features required for systematics. They are not useful for a pharmacologist in …

The Synthesis Of Various Substituted 3-Amino-7-Hydroxy-2,2-Dimethyltetralins And Their Opioid-Related Activities, David Alan Lippman

University of the Pacific Theses and Dissertations

A series of aminotetralones and aminotetralins were synthesized from the common intermediate F, 3-amino-2,2-dimethyl-7-methoxy- 1-tetralone. The final compounds derived from F were simple substituted and/or reduced analogues. The products would allow a progressive structure activity relationship to be drawn based on pharmacological testing.

The common intermediate F was synthesized utilizing a six step procedure starting with p-methoxyphenylacetic acid. The overall yield from the precursor to the F:HC1 was 25%. Compound F was either O-demethylated to form 3-amino-2,2-dimethyl-7-hydroxy-l-tetralone (I) or was dimethylated on the amine and subsequently O-demethylated to yield the 3-dimethylamino-7-hydroxy-2,2-dimethyl-l-tetralone (J). The last major modification was the reduction of …

Computerized Formulation And Optimization Of Medicated Chewing Gum, Daniel J. Berky

University of the Pacific Theses and Dissertations

Sixty Four caffeinated chewing gum preparations were formulated by varying the amounts of (i) cinnamaldhyde, (0-0.75%), (ii) docusate (0-0.5%) and (iii) sucrose (40-60%). The gum base consisted of 33.33% yellow beeswax and 66.66% polyisobutylene MH, and was added, adjusting for a final weight of 2 grams per gum. The amount of caffeine was maintained at 100mg. The preparations were subjected to an in vivo release study as well as a hedonic survey with a panel of student volunteers.

Data were analyzed by using multiple linear regression on a mainframe computer. The resulting mathematical model was used to predict a theoretically …

The Biochemistry Of Vascular Smooth Muscle In The Spontaneously Hypertensive Rat, John Edward Taylor

University of the Pacific Theses and Dissertations

Cyclic adenosine 3’,5’-monophosphate (cAMP) was first described as the mediator of the glycogenolytic effect of epinephrine and glucagon in the liver almost two decades ago. It has since been found that cAMP may mediate the effects of a number of hormones and neurohormones, and this observation has led to the development of the second messenger hypothesis of hormone action. According to the second messenger theory, the hormone or first messenger brings information to the cell, whereas, the second messenger (cAMP) transfers this information into intracellular events. More recent evidence has described the existence of an additional second messenger, cyclic guanosine …

Anticoagulant Half-Life Of Heparin In Human Subjects With Normal And Impaired Renal Function., Paul James Perry

University of the Pacific Theses and Dissertations

Numerous investigators have noted that individuals vary widely in their response to the anticoagulant, heparin. Animal model3 have suggested that patients with depressed renal function would be expected to clear heparin from the blood at a slower rate than patients with normal renal function.

Utilizing the Activated Coagulation Time clotting test, a method was developed to determine the anticoagulant half-life of heparin. The study calculated the half-life of heparin in a group of individuals with normal renal function and a population of patients in chronic renal failure. Intravenous heparin doses of 0,3 units/ml and 0.6 units/ml of blood were administered …

A Pharmacologic Investigation Of The Antiinflammatory Activity Of Cryogenine, Donald Saadia Kosersky

University of the Pacific Theses and Dissertations

This study was conducted in an attempt to define the anti inflammatory efficacy of cryogenine, the major alkaloid of Heimia salicifolia Link and Otto. The anti inflammatory effects produced by cryogenine, phenylbutazone, indomethacin, mefenamic acid, paramethasone, hydrocortisone and 6-mercaptopurine were compared considering the sequential changes in various motameters during the course of adjuvant-induced polyarthritis in rats. Polyarthritis was induced by the subplantar injection of a suspension of heat-killed Mycobacterium butyricus in mineral oil into the right hind paw of Sprague-Dawley rats. The manifestations of the diseases were monitored in terms of hind paw swelling, subjective appearance of secondary lesions, impairment …