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Articles 1 - 7 of 7

Full-Text Articles in Molecular Biology

Towards Elucidation Of The Mechanism Of Biological Nanomotors, Zhengyi Zhao Jan 2016

Towards Elucidation Of The Mechanism Of Biological Nanomotors, Zhengyi Zhao

Theses and Dissertations--Pharmacy

Biological functions such as cell mitosis, bacterial binary fission, DNA replication or repair, homologous recombination, Holliday junction resolution, viral genome packaging, and cell entry all involve biomotor-driven DNA translocation. In the past, the ubiquitous biological nanomotors were classified into two categories: linear and rotation motors. In 2013, we discovered a third type of biomotor, revolving motor without rotation. The revolving motion is further found to be widespread among many biological systems. In addition, the detailed sequential action mechanism of the ATPase ring in the phi29 dsDNA packaging motor has been elucidated: ATP binding induces a conformational entropy alternation of ATPase ...


Elucidating Proteasome Catalytic Subunit Composition And Its Role In Proteasome Inhibitor Resistance, Kimberly C. Carmony Jan 2016

Elucidating Proteasome Catalytic Subunit Composition And Its Role In Proteasome Inhibitor Resistance, Kimberly C. Carmony

Theses and Dissertations--Pharmacy

Proteasome inhibitors bortezomib and carfilzomib are FDA-approved anticancer agents that have contributed to significant improvements in treatment outcomes. However, the eventual onset of acquired resistance continues to limit their clinical utility, yet a clear consensus regarding the underlying mechanisms has not been reached.

Bortezomib and carfilzomib are known to target both the constitutive proteasome and the immunoproteasome, two conventional proteasome subtypes comprising distinctive sets of catalytic subunits. While it has become increasingly evident that additional, ‘intermediate’ proteasome subtypes, which harbor non-standard mixtures of constitutive proteasome and immunoproteasome catalytic subunits, represent a considerable proportion of the proteasome population in many cell ...


Chemoenzymatic Studies To Enhance The Chemical Space Of Natural Products, Jhong-Min Chen Jan 2015

Chemoenzymatic Studies To Enhance The Chemical Space Of Natural Products, Jhong-Min Chen

Theses and Dissertations--Pharmacy

Natural products provide some of the most potent anticancer agents and offer a template for new drug design or improvement with the advantage of an enormous chemical space. The overall goal of this thesis research is to enhance the chemical space of two natural products in order to generate novel drugs with better in vivo bioactivities than the original natural products.

Polycarcin V (PV) is a gilvocarcin-type antitumor agent with similar structure and comparable bioactivity with the principle compound of this group, gilvocarcin V (GV). Modest modifications of the polyketide-derived tetracyclic core of GV had been accomplished, but the most ...


Amalgamation Of Nucleosides And Amino Acids In Antibiotic Biosynthesis, Sandra H. Barnard Jan 2013

Amalgamation Of Nucleosides And Amino Acids In Antibiotic Biosynthesis, Sandra H. Barnard

Theses and Dissertations--Pharmacy

The rapid increase in antibiotic resistance demands the identification of novel antibiotics with novel targets. One potential antibacterial target is the biosynthesis of peptidoglycan cell wall, which is both ubiquitous and necessary for bacterial survival. Both the caprazamycin-related compounds A-90289 and muraminomicin, as well as the capuramycin-related compounds A-503083 and A-102395 are potent inhibitors of the translocase I enzyme, one of the key enzymes required for cell wall biosynthesis. The caprazamycin-related compounds contain a core nonproteinogen b-hydroxy-a-amino acid referred to as 5’-C-glycyluridine (GlyU). Residing within the biosynthetic gene clusters of the aforementioned compounds is a shared open reading ...


Investigating Therapeutic Options For Lafora Disease Using Structural Biology And Translational Methods, Amanda R. Sherwood Jan 2013

Investigating Therapeutic Options For Lafora Disease Using Structural Biology And Translational Methods, Amanda R. Sherwood

Theses and Dissertations--Molecular and Cellular Biochemistry

Lafora disease (LD) is a rare yet invariably fatal form of epilepsy characterized by progressive degeneration of the central nervous and motor systems and accumulation of insoluble glucans within cells. LD results from mutation of either the phosphatase laforin, an enzyme that dephosphorylates cellular glycogen, or the E3 ubiquitin ligase malin, the binding partner of laforin. Currently, there are no therapeutic options for LD, or reported methods by which the specific activity of glucan phosphatases such as laforin can be easily measured. To facilitate our translational studies, we developed an assay with which the glucan phosphatase activity of laforin as ...


Role Of Cyclooxygenase-2 In Abdominal Aortic Aneurysms In Mice, Kamalika Mukherjee Jan 2012

Role Of Cyclooxygenase-2 In Abdominal Aortic Aneurysms In Mice, Kamalika Mukherjee

Theses and Dissertations--Pharmacy

Abdominal aortic aneurysm (AAA) is a chronic inflammatory disease with no available pharmacological treatment. AAA formation reduces the structural integrity of the vessel and increases the susceptibility to rupture. The inflammatory response within human aneurysmal tissue is characterized by increased expression of cyclooxygenase-2 (COX-2). Similarly, in a mouse model of the disease induced by chronic Angiotensin II (AngII) infusion, we have shown that COX-2 expression in the abdominal aortic smooth muscle layer increases early in the development of the disease. Furthermore, genetic or pharmacological inactivation of COX-2 prior to disease initiation reduces AAA incidence.

The current study utilized nonhyperlipidemic mice ...


Dissecting The Biosyntheses Of Gilvocarcins And Ravidomycins, Madan Kumar Kharel Jan 2010

Dissecting The Biosyntheses Of Gilvocarcins And Ravidomycins, Madan Kumar Kharel

University of Kentucky Doctoral Dissertations

Gilvocarcin V (GV) and ravidomycin (RMV) exhibit excellent antitumor activities in the presence of near-UV light at low concentration maintaining a low in vivo cytotoxicity. Although, the exact molecular mechanism for in vivo actions of these antibiotics has yet to be determined, a [2+2] cycloaddition reaction of the vinyl side chain with DNA thymidine residues in addition to the inhibition of topoisomerase II and DNAhistone H3 cross-linking are reported for the GV’s mechanism of action. Such activities have made these molecules interesting candidates for the biosynthetic investigation to generate analogues with improved activity/solubility. Previous biosynthetic studies have ...