The Molecular Mechanisms Responsible for the Assembly of Spider Silk Fibers
Abstract
The ability to replicate spider silk assembly in the laboratory continues to elude scientists. It is our belief that this is due to a lack of understanding regarding the molecular underpinnings for converting the protein-rich fluid in the spiders gland to an insoluble fiber with outstanding mechanical properties that exceed most man-made materials. This proposal describes a research plan designed to elucidate the molecular structure, dynamics and interactions of the silk proteins in the gland fluid and determine the important biochemical triggers responsible for converting this gel-like liquid to fibers with unparalleled, yet diverse mechanical properties. The need for such an understanding has been noted in the recent AFOSR funding opportunity, BAA-AFOSR-2015, Natural Materials, Systems and Extremophiles section, where an understanding of the mechanisms for natural directed assembly was highlighted (pp. 48-49). We propose to use a combination of nuclear magnetic resonance (NMR) approaches including solid-state NMR, high-resolution NMR and Diffusion NMR techniques in conjunction with cryo-electron microscopy (cryo-EM) and X-ray diffraction to study the various spider silk producing glands in their native state and under different biochemical conditions. We aim to characterize the dynamics of the silk proteins within the glands where there is now strong evidence for oligomeric silk protein assembly. Some of this evidence comes from diffusion NMR and cryo-EM research we performed in our current (but ending) AFOSR grant. Recently, we succeeded in developing an approach to grow spider silk fibers directly from the gland fluid by changing the biochemical conditions such as pH. Much of the proposed work will involve characterizing the kinetics of silk fiber assembly with this approach and the molecular structure of the resulting fibers with a range of solid-state NMR and diffraction techniques.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 29, 2021
- Accession Number
- AD1230182
Entities
People
- Gregory Holland
Organizations
- Salk Institute for Biological Studies