  
|
|
|
The Department of Chemistry at the University of Kentucky organizes an annual Symposium on Chemistry and Molecular Biology. This Symposium was established in honor of Anna S. Naff, a University of Kentucky graduate, through the generous support of Dr. Benton Naff of NIH. The Symposium has an interdisciplinary character and is attended by students and faculty from Chemistry, Engineering, Biology, Biochemistry, Pharmacy, and Medicine. The symposium is also attended by faculty and students from colleges and universities in Kentucky and the contiguous States.
The speakers for the 1999 Symposium are Prof. Chi-Huey Wong, Prof. Laura L. Kiessling, Prof. Ole Hindsgaul, and Prof. Fred Brewer.
This year the symposium will be held in the Hospital Auditorium, HG-611, at the UK Medical Center, location G5 on the Campus Guide Map. Parking is most convenient at the Hospital Parking Garage, location G6-H6 on the Campus Guide Map. A lunch with the speakers will follow at the University of Kentucky Faculty Club.
*Winner of the 1999 Claude S. Hudson Award in Carbohydrate Chemistry (American Chemical Society).
**1999 Arthur C. Cope Scholar (American Chemical Society).
A Carbohybrid
1Nilsson et al, Biorg. Med. Chem. 6 (1998) 1563.
3Brewer, C. F. Chemtracts - Biochem. & Molec. Biol. 6 (1996) 165-179.
[Previous Naff Symposia]
[Naff Symposium Home Page]
[Other Department Seminars]
[Chemistry Home Page]
This page was last updated
8:30 am
Prof. Chi-Huey Wong*
Scripps Research InstituteChemoenzymatic Approach to Carbohydrate-Mediated Biological Recognitions
This lecture will present our recent work on the development of new
chemoenzymatic approaches to tackle the problem of carbohydrate-mediated
biological recognition processes. Studies of selectin-carbohydrate
interaction associated with infectious and inflammatory diseases and
development of new methods for the synthesis of carbohydrates and their
conjugates, carbohydrate mimetics and mechanism-based inhibitors of
glycosyltransferases will be discussed.
9:30 am
Prof. Laura L. Kiessling**
University of WisconsinProbing Saccharide Recognition with Synthetic, Multidentate Ligands;
Saccharides employ unique mechanisms to mediate biologically and medically important recognition events. One key feature that distinguishes protein - carbohydrate interactions from traditional receptor-ligand binding events is that the former often requires a multivalent display of saccharide ligands. We have developed the ring-opening metathesis polymerization (ROMP) as a new method to synthesize multivalent arrays. Using this approach, we have been systematically exploring multivalent protein - saccharide binding to illuminate features that give rise to high functional affinities. In addition, we have found new functions for multidentate saccharide ligands, suggesting the in vivo display of saccharide clusters may have functions beyond protein - carbohydrate complexation. We have used our multivalent displays to inhibit cell - cell interactions, promote proteolytic cleavage of the protein L-selectin from the cell surface, and to control signal transduction pathways in bacterial chemotaxis.
or, Carbohydrates: Not Just for Breakfast Anymore
10:45 am
Prof. Ole Hindsgaul
University of AlbertaSolid-Phase Synthesis and Screening of "Carbohybrid" Mixtures
Solid phase combinatorial chemistry has been used to add molecular diversity to minimal carbohydrate structures in an effort to produce ligands for carbohydrate-binding proteins. We term the resulting molecules "carbohybrids" since they contain a sugar, a small organic ring-spacer and a derivatized amine, usually an amino acid. The solution synthesis of such compounds has already been reported1 and the chemistry has now been extended to the solid phase using unprotected sugars and a trityl-linker. The synthesis of a 300-member beta-GlcNAc carbohybrid library illustrates the method. The compounds, produced as mixtures, are screened using Frontal Affinity Chromatography with MS-detection2 which can determine the binding constants for individual compounds present in a complex mixture.
2Schriemer et al, Angew. Chemie 37 (1998) 3383.
11:45 am
Prof. Fred Brewer
Albert Einstein College of MedicineX-Ray Crystal Structures of Lectin-Carbohydrate Cross-Linked Complexes
Lectin binding to the surface of cells leads to cross-linking of
glycoconjugate receptors, including glycoproteins and glycolipids, which,
in many cases, is related to a variety of biological signal transduction
processes. We have observed that many naturally occurring cell surface
oligosaccharides are multivalent and capable of binding and precipitating
with specific lectins.3 These cross-linking interactions lead to a new
source of binding specificity, namely, the formation of homogeneous
carbohydrate-lectin cross-linked lattices, even in the presence of mixtures
of the molecules. Our recent studies show that many of these lattices are
highly ordered and often crystalline. For example, the soybean agglutinin,
a tetrameric GalNAc/Gal specific lectin from Glycine max, forms crystalline
cross-linked lattices with four isomeric analogs of the biantennary blood
group I carbohydrate antigen.4 We will describe the x-ray crystal structures of these
complexes as well as more recent structural studies which provide insight
into the structure-function properties of multivalent lectins and
carbohydrates.
4Olsen et al. Biochemistry 36 (1997) 15073-15080.
