Collagen-like

Figure 14.2 Models of a collagen-like peptide with a mutation Gly to Ala in the middle of the peptide (orange). Each polypeptide chain is folded into a polyproline type II helix and three chains form a superhelix similar to part of the collagen molecule. The alanine side chain is accommodated inside the superhelix causing a slight change in the twist of the individual chains, (a) Space-filling model, (b) Ribbon diagram. Compare with Figure 14.1c for the change caused by the alanine substitution. (Adapted from J. Bella et al.. Science 266 75-81, 1994.)...

Bella, J., et al. Crystal and molecular structure of a collagen-like peptide at 1.9 A resolution. Science 266 ... 

FIGURE 6.18 Poly(Gly-Pro-Pro), a collagen-like right-handed triple helix composed of three left-handed helical chains. (Adaptedfrom Miller Scheraga, H. A., 1976, Calculation of the... 

Collagen-like (ColQ) tailed forms or asymmetric multimers Characterized by triple helical structure of three collagenic subunits Q, each associated with... 

The detection of the collagen-like threefold symmetric polypeptides, polyglycine4 and polyproline5, was the first help to elucidate the collagen structure using a synthetic peptide model. 

Table 5. Formation of the negatively and positive sequences in water and methanol, indicated by the collagen-like CD spectra and by the shape of the temperature transition curve...

Goodman, M., Feng, Y, Melacini, G., and Taulane, J. P. A template-induced incipient collagen-like triple-helical struc-... 

Y. Collagen-like triple helices incorporating peptoid residues. J. Am. Chem. Soc. 

Sylvestre, P. Couture-Tosi, E. Mock, M. A collagen-like surface glycoprotein is a structural component of the Bacillus anthracis exosporium. Mol. Microbiol. 2002, 45,169-178. 

Reversible gelation is often encountered in bio-polymeric systems. Typical examples are solutions of polypeptide residues derived from animal collagen [82-84]. In these systems, ordered collagen-like triple helices form the physical crosslinks. 

Ackerman, M.S., Bhate, M., Shenoy, N., Beck, K., Ramshaw, JA.M. and Brodsky, B. (1999) Sequence dependence of the folding of collagen-like peptides - single amino acids affect the rate of triple-helix nucleation. Journal of Biobgical Chemistry 274, 7668-7673. 

Kamitakahara, M., Ohtsuki, C., Morihara, Y., Ogata, S. and Tanihara, M. (2005) Hydroxyapatite deposition on collagen-like polypeptide modified with silanol groups, in Archives of BioCeramics Research (eds F. Watari, T. Akazawa, M. Uo, T. Akasaka), Vol.5, pp. 210-213. 

Stabilization of Short Collagen-Like Triple Helices by Exogenous Trimerization... 

Collagen is the most abundant extracellular matrix protein family in vertebrates. Proteins in the collagen superfamily all have three polypeptide chains with the required -Gly-Xaa-Yaa- repeated sequence, where Xaa and Yaa are frequently proline and 4-hydroxyproline, respectively. At present, more than 30 molecular species of vertebrate proteins called collagen are classified into 28 types as type I, II, III,..., XXVIII. They are typically called type N collagen , or collagen N . In addition, there are many more collagen-like proteins that... 

Synthetic peptides have been extensively used to study the thermal stability and folding of the triple helix. These peptides can be synthesized as either single chains or cross-linked peptides. Early on, such peptides were synthesized by polycondensation of tri- or hexapeptides, which led to a broad mass distribution that was difficult to separate. With the advances of solid-phase synthesis methods, peptides with defined chain length became available. The most studied collagen-like peptides are (Gly-Pro-Pro) or (Pro-Pro-Gly) and (Gly-Pro-4(if)Hyp) or (Pro-4(if)Hyp-Gly) with n varying from 5 to 15. Sutoh and Noda" " introduced the concept... 

Kirschenbaum, D. M. Schulman, N., and Halpern, M. (1986). Earthworms produce a collagen-like substance detected by the garter snake vomeronasal system. Proceedings of the National Academy of Sciences, USA 83,1213-1216. 

Figure 13.3 A schematic summary of the galectins. (a) Galectins with one carbohydratebinding domain and (b) their noncovalent dimers, (c) Galectin-3 has a collagen-like domain and a carbohydrate-binding domain, (d) Galectins with two covalently hnked carbohydratebinding domains.

Collagen-like Polyproline type II (A-y-Gly) repeat Helix nucleation followed by zippering fiber formation still a significant challenge Perpendicular... 

Figure 14.14 A zwitterionic collagen-like peptide is shown to self-assemble into relative thick fibers displaying a native collagen-like D-spacing pattern. Reprinted from Rele et al. (2007). Copyright 2007 American Chemical Society.

The inner layer of the corneal stroma is a dense membrane of collagen like the basal membrane of the monolayer of corneal endothelium. Descemets membrane is transparent with a thickness varying from 7 to 20 pm, according to the age of the individual. Conjunctiva and cornea host nerve endings of high density in the snperhcial and basal layers. The cornea at the limbns smoothly changes to sclera with interconnected nontransparent collagen hbrils. 

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