Professor of Pathology
Address and Contact:
Department of Pathology
University of Texas-Houston
Medical School
P.O. Box 20708
Houston, TX 77225-0708
James.K.Stoops@uth.tmc.edu
(713) 500-5345
(713) 500-0730 (FAX)
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James K. Stoops, Ph.D. Professor of Pathology Address and Contact: Department of Pathology University of Texas-Houston Medical School P.O. Box 20708 Houston, TX 77225-0708 James.K.Stoops@uth.tmc.edu (713) 500-5345 (713) 500-0730 (FAX) |
Current Research Interests
Structure-function Studies of Macromolecules of Biological
Interest.
Research activities involve studies of the structural organization
and function of macromolecules such as the fatty acid synthase,
pyruvate dehydrogenase, urease, human alpha2-macroglobulin,and
human complement proteins. The multifaceted approaches described
below and the diversity of topics under investigation offer the
student an excellent background in structural biology. Cryo- and
stain electron microscopy are employed to record the images of
the macromolecules. Electron micrographs are processed in our
computer science laboratory to enhance structural features of
the molecule and to reconstruct its three-dimensional structure.
Functional studies utilize physicochemical methods to investigate
the mechanisms of some of these proteins. An adequately equipped
biochemistry laboratory complement this research. We have recently
completed three-dimensional reconstructions of various forms of
human alpha2-macroglobulin. Alpha2-Macroglobulin
is a glycoprotein (Mr = 720,000) that functions as one of
the major proteinase inhibitors in the plasma of vertebrates.
It is thought to serve as a general scavenger of proteinases,
thereby protecting blood and tissue proteins from degradation.
Inhibition of a proteinase by alpha2-macroglobulin
is unique in that the molecule undergoes a large structural change
on reaction with a proteinase resulting in its entrapment. Our
three-dimensional structures of native and the alpha2-macroglobulin
proteinase complex delineated the position of the bound proteinase
in the structure and showed the manner in which alpha2-macroglobulin
sequesters the proteinase.
Recent Publications
Gaertner, T.R., Kolodziej, S.J., Wang, D., Kobayashi, R., Koomen, J.M., Stoops, J.K., and Waxham, M.N. 2004, Comparative Analyses of the 3-Dimensional Structures and Enzymatic Properties of a, ß, ? and d Isoforms of Ca2+-calmodulin Dependent Protein Kinase II. J. Biol. Chem. 279:12484-12494.
Mullapudi, S., Pullan, L., Bishop, O.T., Khalil, H., Stoops, J. K., Beckmann, R., Kloetzel, P.M., Kruger, E., and Penczek, P.A. 2004, Rearrangement of the 16S Precursor Subunits Is Essential for the formation of the Active 20S Proteasome. Biophysical J. 87: 4098-4105.
Pullan, L., Mullapudi, S., Huang, Z., Baldwin, P.R., Chin, C., Sun, W., Tsujimoto, S., Kolodziej, S.J., Stoops, J.K., Lee, J.C., Waxham, M.N., Bean, A.J., and Penczek, P.A. 2006, The Endosome-Associated Protein Hrs Is Hexameric and Controls Cargo Sorting as a “Master Molecule”. Structure 14: 661-671.
Zhou, Z.H., Stoops, J.K. and Krueger, G.R.F., 2006, Ultrastructure and Assembly of Human Herpesvirus-6 (HHV-6). In Perspective Medical Virology 12, pp 11-21, Eds. G. Krueger and D. Ablashi, Elsevier, Amsterdam.