UT Chem/Biochem Dept

The 2001-2002 Beckman Scholars: Stella Kijung Kang (Maeng), MD Faculty Mentor: Professor Angela M. Belcher Length of term: Fall 01, Spring 02, Summer 02; Summer 01 was spent in the SMART program at Baylor College of Medicine. Honors & Awards:University Honors (Fall 98, Spring 99, Fall 99, Spring 00, Fall 00, Spring 01, Fall 01, Spring 02); Deans Scholars Program (Fall 2000 ­ Spring 2002); Unrestricted Endowed Presidential Scholarship (2000); Ralph Steiner M.D. Scholarship (2000); Undergraduate Research Fellowship (2000); Friends of Chemistry Scholarship (2000); Phi Beta Kappa (2002); F.C. Valentine Student Research Grant in Urology awarded by the New York Academy of Medicine (2004); Alpha Omega Alpha (2006); Memorial Sloan-Kettering Cancer Center Summer Student Research Fellowship (2006) Publications: Ohebshalom MM, Maeng SK, Chen J, Poppas DP, Felsen D. Pressure induces nitric oxide production by human ureteral cells in vitro. AUA, San Antonio. J Urol 173: S137, 2005. ; Maeng S. Characterization of the effect of pressure on nitric oxide (NO) production by urothelial cells. New York Academy of Medicine oral presentation, 2004. Where is she now? Graduated with Bachelor of Arts in Plan II Honors with Highest Honors and with Special Honors in Plan II, May 2002, and with a Second Major in Biochemistry, Aug 2002. Stella spent a year teaching English in China, got her MD from Weill Cornell Medical College, completed a radiology residency at NYU, and is now an Assistant Professor of Radiology, at NYU School of Medicine. How can I contact her? sk_maeng at yahoo.com Beckman research project in the Belcher group: RNA-Directed Design of Nanostructures using Peptides with Nanocrystal Binding Specificity

The use of biological systems to design the next generation of microelectronic devices offers a possible solution to the problems posed by traditional materials processing methods. While lithographic technology is reaching its limitations, biological systems which routinely form organic-inorganic structures (e.g. bones) by a variety of processes provide a way to selective, self-organizing design of nanoscale building blocks. In order to harness the biological recognition of inorganic substances occurring in nature, Dr. Belcher employs peptides evolved to bind specifically to a certain inorganic substrates. The study of such biological-inorganic specificity of peptides to specific inorganic substrates lays the groundwork for directing the self-assembly of electronic materials. Furthermore, RNA templates can be used to dictate the assembly of nanostructures through polypeptide synthesis. The binding specificity of peptides to inorganic substrates were established through selection of phage displaying the peptides. The Belcher group uses a peptide combinatorial approach to identify proteins that select for and specifically bind to inorganic nanoparticles such as semiconductor quantum dots or nanoparticles of iron and tin oxides. Phage display libraries are used to select peptide sequences that will bind to the materials. This phage library is based on a combinatorial library of random peptides of a given length (e.g. 7-mer or 12-mer) that are fused to the pIII minor coat protein of the filamentous coliphage M13. Five copies of the pIII coat protein are located on one end of the phage, therefore displaying five copies of the fused random protein. This approach of using a phage display links the peptide-substrate interaction with the DNA that encodes that interaction. Thus, optimizing the strength of peptide-substrate binding is also approached genetically.

My project harnesses the established specificity of peptides to inorganic substrates, RNA templates can be utilized through their function of programming polypeptide chain formation. The process involves charging of tRNA with respective amino acid, attaching a cross linker and quantum dot, and finally translating the tRNA to organize the quantum dots. By varying the type and number of amino acids in the spacer, we can change the distance between the quantum dots. The length and chemical character of the spacer amino acids will also affect the secondary structure of the peptide. Our goal in using the RNA template includes both the elucidation of ribosome function and translation, as well as the design of biological-inorganic heterostructures using nanocrystals.