Department of Biology

Faculty Research

Dr. Verlie A. Tisdale, Ph.D. (Dean of the School of Natural Sciences & Mathematics & Prof./Biology)

Dr. Tisdale is the Chair of the Division of Natural Sciences and Mathematics. Her research interest is biochemical analysis of enzymes. Current duties include administration of curricular design to prepare students for graduate and health professions school by challenging them to become conceptual learners and critical thinkers. She also advises student researchers on their research projects: 1) design, 2) methodology, 3) analyses, 4) writing and 5) presentation.

Dr. Omar Bagasra, M.D., Ph.D. (Prof. & Dir./SC Center for Biotechnology)

Dr. Bagasra is the Director of Claflin University’s South Carolina Center for Biotechnology. His research interests have long been associated with the study of HIV and AIDS. In fact, he has been on the trail of the virus since 1981—the year of the first scientific report. For the past several years, he has focused on trying to gain insight into modes of virus transmission, natural immunities to retro viral infection, as well as the development of gene therapy treatments for HIV-1. Recently, he has concentrated on the molecular pathogenesis of prostate and breast cancers and in the development of edible vaccines for HCV and malaria with funding from the Department of Defense and the South Carolina Biomedical Research Infrastructure Network . His unswerving dedication to his work has resulted in over 200 scientific articles, book chapters, and books. He also has national and international collaborations with numerous well-known scientists, and many of these colleagues received training in molecular morphology in his laboratory at Lincoln University. He is the inventor of the in situ PCR technique. He also keeps a hand in clinical work—he is currently board-eligible in anatomic pathology and a diplomat of the American Board of Medical Laboratory Immunology, and the American boards of Forensic Examiners and Forensic Medicine.

Dr. Jianguo Chen, Ph.D. (Assoc. Prof./Biology & Dir. of the Genomics & Sequencing Lab.)

Dr. Chen joined the department in August 2003. He comes to Claflin from a position as a Senior Scientist at Applied Biosystems, Inc. He has significant experience with methods development for microsatellite analysis and sequencing. Dr. Chen is the Director of our Genomics and Sequencing laboratory.

Dr. Kamal Chowdhury, Ph.D. (Prof./Biology)

Dr. Chowdhury has recently joined the Biology department as plant / agricultural biotechnologist to develop and direct a plant biotechnology program at Claflin. Before joining Claflin, he was a Senior Scientist with Arborgen, world’s leading forest biotechnology company. Prior to that he was the Group Leader of tissue culture section of International Paper, world’s largest paper and pulp company. His research contribution in plant biotechnology area includes 38 publications in 18 peer-reviewed journals on 14 crop species in the area of quantitative and molecular genetics, plant tissue culture and genetic engineering. In addition to working on agricultural biotechnology, his future research interest is in the area of plant-made-pharmaceuticals and utilization of transgenic plants for phytoremediation.

Dr. Randall Harris, Ph.D. (Ass. Prof./Biology)

Once considered a harmless commensal, Moraxella catarrhalis is now recognized as significant cause of respiratory tract infections in humans.  The microbe is third leading cause of otitis media in infants and children and infectious exacerbations in patients with chronic bronchitis.  My laboratory studies the interaction between M. catarrhalis and the innate immune system. The laboratory is currently focused on the molecular mechanisms by which M. catarrhalis survives within neutrophils.  Neutrophils represent an early barrier to infection through their ability to ingest, kill, and degrade microorganisms.  We have identified genes responsible for in vitro resistance to reactive oxygen species and cationic peptides, two major classes of neutrophil antimicrobial molecules.  We are currently defining how these genes are regulated and their contribution to M. catarrhalis survival within neutrophils.

Dr. Samina N. Hassanali (Assoc. Prof./Biology)

MicroRNAs (miRNAs) are small RNAs that regulate eukaryotic gene activity at the post-transcriptional level. Close to one thousand miRNAs have been characterized up to now and each miRNA is assumed to regulate several target mRNAs. MiRNAs are assumed to regulate the activity of mammalian mRNAs, including such involved in the control of apparently all important aspects of cellular regulation like growth, development, differentiation, metabolism and chromatin structure.

MiRNAs are processed in the nucleus from primary precursors, exported to the cytoplasm and then further processed to ~22bp miRNA duplexes with 3'-overhangs. MiRNAs are believed to originally have evolved to regulate the viral genes and serve as defense against exogenous viruses. The opportunity to selectively silence viral mRNA involved in the cause of human disease represents an exciting new frontier for therapeutical research.

HCV is a serious infectious disease representing a major public health concern affecting 170 million people worldwide. Most current and emerging anti-HCV therapies target viral genes and are therefore prone to the emergence of resistance. However, targeting specific miRNAs homologous to the host hepatocellular miRNAs has not been looked into which is required for viral replication. My lab is studying specific miRNAs which are homologous to HCV genes. This application may be a target for novel approaches in the treatment of HCV infection.

In this study, the Huh-7.5 cell model are being used so as to improve our understanding of HCV replication and the testing for antiviral molecules.

Dr. Nicholas Panasik, Ph.D. (Assoc. Prof./Biology/Chemistry)

The eight stranded a/ b barrel protein fold is the largest family of protein structures (representing at least 10% of all known protein structures) and has the widest range of enzyme functions. My research focuses on elucidating the structural basis for folding specificity and thermodynamic stability in this class of enzymes and the future application of those principles in protein design. Specifically, I use random PCR mutagenesis to create a library of genetic variants for a variety of enzymes including beta-galactosidase. These variants are placed in an expression host that is a beta-galactosidase negative yet positive for the lactose transport genes. A temperature selection is applied. Using chromogenic substrates for screening, or nutrient restriction for selection, variants that display the selected phenotype (activity or stability at higher or lower temperature) can be selected. These variants are subjected to future rounds of mutagenesis and selection until variants with dramatically different enzymatic properties are produced. Using multiple successes from these “Directed Evolution” experiments, coupled with careful analysis of structure, patterns of mutations begin to emerge. These patterns help us posit generalized, fold-specific, molecular mechanisms of protein structural adaptation to temperature. These principles are then tested using site directed mutagenesis and rational design.