Title

Characterization of gumfoot threads from Latrodectus hesperus.

Poster Number

7

Format

Poster Presentation

Abstract/Artist Statement

Latrodectus hesperus builds cobwebs consisting of three distinct structures: the retreat, scaffolding meshwork and vertical gumfoot threads. Vertical gumfoot threads function in the capture of ground moving prey. Material properties were determined by stretching 41 . gumfoot threads from 8 spiders until breaking. The stress- strain curve shows an initially stiff region, average of 5. 0 GPa. At 1-2 % strain the stiffness decreased to an average of 2. 7 GPa. This yield point suggests a significant change in the molecular bonds of the silk. The threads break at an average stress of 0.47 GPa and a strain of 17.5%. The gumfoot thread consists of high molecular weigh proteins on the order of 210 kD and 240 kD. The mole percent amino acid composition. suggest high percents of glycine and alanine, both small nonpolar side chains. Analysis of the material properties, polypeptide composition and mole percent amino acid composition suggests the gumfoot threads are distinct fibers. Supported by NSF (DBI 99-96072)

Location

DeRosa University Center

Start Date

1-5-2001 9:00 AM

End Date

1-5-2001 5:00 PM

This document is currently not available here.

Share

COinS
 
May 1st, 9:00 AM May 1st, 5:00 PM

Characterization of gumfoot threads from Latrodectus hesperus.

DeRosa University Center

Latrodectus hesperus builds cobwebs consisting of three distinct structures: the retreat, scaffolding meshwork and vertical gumfoot threads. Vertical gumfoot threads function in the capture of ground moving prey. Material properties were determined by stretching 41 . gumfoot threads from 8 spiders until breaking. The stress- strain curve shows an initially stiff region, average of 5. 0 GPa. At 1-2 % strain the stiffness decreased to an average of 2. 7 GPa. This yield point suggests a significant change in the molecular bonds of the silk. The threads break at an average stress of 0.47 GPa and a strain of 17.5%. The gumfoot thread consists of high molecular weigh proteins on the order of 210 kD and 240 kD. The mole percent amino acid composition. suggest high percents of glycine and alanine, both small nonpolar side chains. Analysis of the material properties, polypeptide composition and mole percent amino acid composition suggests the gumfoot threads are distinct fibers. Supported by NSF (DBI 99-96072)