The collagen triple helix is a unique protein fold found in all domains of life where is has diverse
roles from imparting structure and strength to tissue, to initiating an immune response. While
many factors affecting the structure and stability of the triple helix have previously been
elucidated, much remains unknown about collagen. Using collagen-mimetic peptides, it is
possible to investigate the molecular structure of the triple helix, determine new pairwise
interactions of amino acids, characterize disease models and also create designer collagens that
will preferentially hybridize to natural collagen-rich tissue. First a selective labeling scheme is
used to thoroughly characterize a well-folded triple helical region, and then to determine the
degree of localized unfolding at the N- and C-termini. Though terminal fraying extends farther
than previously shown, small sequence alterations at the N-terminus have a drastic influence on
local stability (~15C). Next, a single register heterotrimeric mimic of the type I collagen disease
Osteogenesis Imperfecta is used to investigate single point glycine mutations in the B chain, the
A chain or both chains. Unlike past reports, a combination of NMR analysis and molecular
modelling is used to generate structures of the mutated helices and visualize the underlying
mechanisms of helix destabilization in OI. For the first time it is proven that these mutations
cause compositional as well as structural disruptions. Additionally, while several hundred
pairwise interactions are possible in the triple helix, to date only two interactions are wellunderstood
and commonly incorporated into CMP design. To expand on the library of known interactions, the structure and stability of helices containing serine, threonine, phospho-serine and phospho-threonine were investigated. Notably, when phospho-serine is paired with lysine a new highly stabilizing (49.5 C) axial interaction is possible. Finally, the design of a collagen type II targeting peptide is described, and NMR, CD and confocal microscopy are used to investigate
the hybridization of the synthetic peptide with the natural partner strands
