The Beckman Research Scholars Awards are made possible by the Arnold and Mabel Beckman Foundation in support of truly exceptional undergraduate students who are committed to a research-based career in Biology or Chemistry. The Beckman Scholars will complete an Honors Thesis on their research.
2009-2010 Beckman Scholars
Ms. Karen Aanensen
Ms. Paowen Wong
Ms. Karen Aanensen
Mentor: Dr. Benhur Lee
Title: Exploring Differing Determinants of Virulence between the Malaysian and Bangladeshi Nipah Viral Envelope Proteins
Dr. Hector Aguilar, Dr. Benhur Lee and Karen Aanensen
Karen Aanensen is a fourth year student, pursuing a degree in Microbiology, Immunology and Molecular Genetic. She conducts research in Dr. Benhur Lee’s lab studying Nipah Virus (NiV). There are two strains of Nipah virus, the Malaysian and Bangladeshi strain, with human mortality rates around 40 percent and 70 percent respectively. During the terminal stage of this infection, severe brain stem dysfunction is observed.
Ms. Aanensen is investigating amino acid differences which may contribute to the differing human mortality rates. Specifically, she is comparing the two strain’s amino acid sequences of the attachment protein (NiV-G). NiV-G uses either ephrin-B2 (B2) or ephrin-B3 (B3) as host-cell entry receptors. B3 but not B2 is found in the brain stem. Therefore, any residue differences that increase NiV’s binding affinity to B3 may increase the host-cell entry efficiency within the brain stem. This may consequently contribute to a more severe brain stem infection, brain stem failure, and a higher mortality rate. Our hypothesis is that certain residues on the Bangladeshi strain of NiV-G result in an increased binding affinity to B3 when compared to the Malaysian strain.
Ms. Aanensen has introduced the Bangladeshi amino acid differences onto the Malaysian strain of NiV-G. She then compared the B2 and B3 binding affinities of the parental strain and mutant strains. This was achieved by expressing the constructs in Chinese Hamster Ovarian cells (which lack B2 and B3 receptors) and developing binding curves of B2 or B3. Preliminary studies suggest that one of the NiV-G mutants may increase the binding affinity to B3. Also, she will be testing mutants in which multiple amino acid residues have been introduced in order to assess if certain residue differences act synergistically. Infections will be carried out using pseudo-typed VSVG virus in order to see if these mutants influence viral infectivity. Finally, she will be investigating differences on the other envelope protein, the fusion protein, which is essential for viral fusion into the host cell.
Ms. Paowen Wong
Mentor: Dr. Richard Kaner
Title: A Simple Process to Synthesize Poly (3-hexylthiophene) Nanofibers Using Initiator-assisted Polymerization
Dr. Richard Kaner and Paowen Wong
Paowen Wong is a Departmental scholar who will complete both of her Master degree in Chemistry and her Bachelor degree in Chemistry-Materials Science in Summer 2010. Since Fall 2008, Wong has worked on the synthesis of poly-3-hexylthiophene (P3HT) nanofibers, an organic semiconductor material which is used in solar cells and field-effect transistor applications.
The synthesis of P3HT nanofibers was investigated via initiator-assisted polymerization. The addition of a chemical initiator during polymerization of P3HT accelerates the kinetics of this reaction, and has been reported to function as a catalyst in the mechanism leading to nanofibers of polythiophene – the parent compound of P3HT. Purification protocols of the final product were studied along with synthetic variables such as temperature, solvent, and length of polymerization time. Transparent conductive thin films of in-house produced P3HT nanofibers were deposited on glass substrates for characterization purposes.
The nanoscale morphology of the polymer was investigated using a scanning electron microscope; it was observed that the aspect ratio of produced nanofibers is controlled by the tailoring of the synthetic reaction conditions. Future goals include the fabrication of field effect transistors using P3HT as the semiconductor active layer; also, the generalization of the herein described procedures will be attempted to target other semi-rigid conducting polymers such as polythiophene derivatives poly (3-alkylthiophene) and poly (3-alkoxythiophene).
Wong sincerely appreciates the support from the Beckman Research Scholarship which provides her with the opportunity to work as an independent researcher at the University of California, Los Angeles from Summer 2009 to Summer 2010. Here, Wong would like to thank Dr. Hasson, Dr. Crosbie and Mr. Flaxman for their assistance. Furthermore, Wong would like to express her gratitude toward Prof. Ric Kaner, Julio D’Arcy, and everyone in the Kaner lab for their continued support.