NIST-University of Maryland, Department of Chemistry and Biochemistry
Seminar Series

This Seminar Series is a joint effort between the National Institute of Standards and Technology (NIST) in Gaithersburg, MD and the University of Maryland in College Park, MD. Seminars will be held at NIST and University of Maryland. If you need additional information on the Seminars, please contact the ACD Webmaster by telephone at 301-975-3108, by facsimile at 301-926-8671, by email at acd_webmaster@nist.gov, or by mail at NIST, 100 Bureau Drive, Stop 8390, Gaithersburg, MD 20899-8390.

February 14, 2003
NIST - Gaithersburg, MD

Kristy J. Reynolds
Department of Chemistry & Biochemistry
University of Maryland, College Park, MD 20742

As the sequencing is completed of many species' genomes, the study of the protein compliment to the genome, or the proteome, has emerged as a dynamic field of research. A common approach to characterizing changed states is comparative proteomics, in which the relative amounts of proteins present in two or more samples are compared. In order to determine the relative amount of the proteins present, a proteolytic method for 18O labeling can be used. Briefly, pools of proteins are enzymatically digested in parallel in H216O and H218O. In the latter pool two atoms of 18O are incorporated into the carboxyl-terminus of each new peptide. Comparative proteomic studies can be performed by mixing the unlabeled peptide pool (generated in H216O) and the isotope labeled peptide pool (from H218O) and analyzing the peptide pairs by mass spectrometry. Relative quantitation information is derived from ratios of the isotope pairs. Tandem mass spectrometry experiments provide sequence information to identify the proteins.

This method is being applied to detect differences in regulation or modification of proteins in the cytosolic fraction of drug-susceptible and adriamycin drug-resistant human breast cancer MCF-7 cell lines. The major cause of failure in breast cancer chemotherapy is the development of multi-drug resistance, and the information derived from these experiments can aid in understanding the mechanism of drug-resistance.

April 4, 2003
NIST - Gaithersburg, MD

Sang Bok Lee
Department of Chemistry and Biochemistry
University of Maryland, College Park, MD 20742

Beginning in the 1980's the Martin research group at the University of Florida has pioneered a versatile approach called template synthesis for preparing nanomaterials. This method entails synthesizing nanoparticles of the desired materials within the pores of a nanopore membrane or other solid. Because the membranes used contain cylindrical pores with monodisperse diameters, corresponding cylindrical nanoparticles are obtained. Depending on the material and the chemistry of the membrane, these cylindrical nanostructures may be either solid (nanowires) or hollow (nanotubes).

We have shown that the template method can be used to make synthetic polymer membranes that contain monodisperse, cylindrical nanotubes that span the complete
thickness of the membrane (10 um). The inside diameter of the nanotubes can be controlled at will, down to molecular dimensions (~ 1 nm). Furthermore these nanotubes
can be composed of nearly any material e.g., carbons, metals, polymers, semiconductors.

One area of interest concerns using these nanotube-containing membranes as highly selective molecular filters for chemical and biochemical separations. We are especially interested in membranes for enantioseparations--one of the most challenging and important problems in modem biomedical science. In addition, we have recently shown that these nanotube-containing membranes can be used for protein separations. We have also shown that these tube-containing membranes can be used in a new approach to sensing. We have achieved detection limits with these nanotube sensors as low as 10 pM. Another area of interest concerns using nanotubes themselves isolated from template membranes for bioseparations and biocatalysis.