The molecular structure of collagen - PhDData

Access database of worldwide thesis




The molecular structure of collagen

The thesis was published by O'Dubhthaigh-Orgel, Joseph Patrick Rosen, in September 2022, University of Stirling.

Abstract:

This thesis describes the study of the molecular packing and organisation of
collagen molecules within a fibril.
The first two chapters describe the background to the study. In Chapter 1, a review of
the extracellular matrix concentrates on the structure and organisation of type I
collagen. Chapter 2 summarises the theory of X-ray diffraction by fibres, and Chapter 3
describes X-ray sources and equipment used in data collection. Data treatments and data
extraction methods (such as simulated annealing) are also discussed.
Chapters4 and 5 present the results of the study. Chapter 4 describes the
determination of the one-dimensional structure of type I collagen to 0.54 nm resolution
using X-ray diffraction and isomorphous derivative phase determination. The
significance of the electron density map is interpreted in light of the known amino acid
sequence, showing possible variations in the nature of the helix pitch. More
importantly, the conformations of the intermolecular crosslink forming non-helical
telopeptides were determined.
Chapter 5 provides a detailed background to the current understanding of the three dimensional
packing structure of collagen, and presents the first model-independent
phase determined structure of a natural fibre – the lateral packing structure of type I
collagen in rat tail tendon. The data extraction methods described in Chapter 3 are
employed to calculate an electron density map of anisotropic resolution, from which the
4
crosslink forming telopeptide segments within the quasi-hexagonal packing structure
are identified. Conclusions are drawn concerning the nature of order/disorder within
collagen fibrils and the validity of the compressed microfibril model of collagen
molecular packing and organisation is discussed.
Chapter 6 summaries the results and evaluates the success of the study. The potential
for development of the techniques and results found for further studies are also discussed.



Read the last PhD tips