Biocompatible and biodegradable, silk has been sought after for replacing a variety of materials, from Kevlar® used in bullet proof vests to sutures used in surgery, yet synthetic silk does not match the incredible mechanical properties of the native material. To further our understanding of fiber formation, it is necessary to analyze the development of silk proteins in silk spinning organisms. β-sheet and helical content of fibers and silk dopes from both spiders and silkworms has been characterized and quantified using a variety of techniques, including Solid-state Nuclear Magnetic Resonance (SSNMR) spectroscopy, X-ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) spectroscopy, but IR-microscopy is the first to trace the development and evolution of protein complexes down an entire gland. IR-microscopy is a simple yet effective method for characterizing biomaterials, allowing spectra to be collected at multiple points along a sample spatial map. Using a SperoQT, the amide I region of IR spectra was analyzed at several points along the major ampullate silk gland of an <i>L. hesperus</i> (black widow) spider to determine changes in protein secondary structure. Similarly, changes in protein secondary structure were determined along a <i>B. mori</i> (silkworm) silk gland, revealing an increase in overall β-character as protein complexes approached the head of the silkworm before entering the duct. IR-microscopy is not only applicable to fiber formation, and developing a successful strategy for utilizing this technique would lead to a quick yet effective method for the characterization of biomaterials in general.

Spider silk fiber formation as a model system for characterizing biomaterials using infrared microscopy

ACS Spring Meeting 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.