Certain orb-weaving spiders are known to recycle their webs, some as often as every day. They accomplish this despite the fact that some web fibers, namely major and minor ampullate silk, are highly resistant to common proteases. Spider proteases that degrade these solid fibers are therefore expected to have novel properties. Using digestive fluid from the orb-weaving spider Nephila clavipes, major ampullate silk-degrading or "silkase" activity was identified. The objective of this research is to determine protein sequences that distinguish peptidase isoforms with and without major ampullate silk-degrading activity. By examining enzymatic and sequence data from several spider species, structural and functional features will be correlated. Enzymatic activities of recombinant and native peptidases will be compared using synthetic or soluble silk fibroins or native silk fibers. To test the hypothesis that certain peptidase sequences are key determinants for the presence of major ampullate silkase activity, altered recombinant peptidases will be analyzed.

Broader Impact: Characterization of a silkase with novel enzymatic features will advance our understanding of enzymes that degrade protease-resistant solid fibers and could lead to new biotechnological applications. Students involved in this research will benefit greatly from the collaboration between research groups interested in protein structure/function relationships from the perspectives of the silk fibers and fiber-degrading peptidases. The research will also provide a rich environment for hosting high school students from underrepresented groups in a summer Student Research Apprenticeship Program and undergraduates receiving NSF-EPSCOR summer research awards.

Agency
National Science Foundation (NSF)
Institute
Division of Molecular and Cellular Biosciences (MCB)
Application #
0236255
Program Officer
David A. Rockcliffe
Project Start
Project End
Budget Start
2003-03-15
Budget End
2007-02-28
Support Year
Fiscal Year
2002
Total Cost
$368,323
Indirect Cost
Name
University of Wyoming
Department
Type
DUNS #
City
Laramie
State
WY
Country
United States
Zip Code
82071