
|
Collagen Clinical StudyIs glycine a surrogate for a D-amino acid in the collagen triple helix? Horng JC, Kotch FW, Raines RT. Collagen is the most abundant protein in animals. Every third residue in a collagen strand is a glycine with varphi, psi = -70 degrees , 175 degrees . A recent computational study suggested that replacing these glycine residues with d-alanine or d-serine would stabilize the collagen triple helix. This hypothesis is of substantial importance, as the glycine residues in collagen constitute nearly 10% of the amino acid residues in humans. To test this hypothesis, we synthesized a series of collagen mimic peptides that contain one or more d-alanine or d-serine residues replacing the canonical glycine residues. Circular dichroism spectroscopy and thermal denaturation experiments indicated clearly that the substitution of glycine with d-alanine or d-serine greatly disfavors the formation of a triple helix. Host-guest studies also revealed that replacing a single glycine residue with d-alanine is more destabilizing than is its replacement with l-alanine, a substitution that results from a common mutation in patients with collagen-related diseases. These data indicate that the glycine residues in collagen are not a surrogate for a d-amino acid and support the notion that the main-chain torsion angles of a glycine residue in the native structure (especially, varphi > 0 degrees ) are critical determinants for its beneficial substitution with a d-amino acid in a protein. PMID: 17189476 [PubMed - as supplied by publisher]
We are strictly a bulk supplier to manufacturers – we do not sell to re-sellers or individuals. Our minimum order size is approximately 25 kilos. We are one of only a few suppliers that carry $5 million product liability insurance for our customers. AHD International LLC is classified as a importer, exporter, manufacturer, distributor of nutritional ingredients depending on the ingredient specified. AHD has 5 warehouse locations across North America and sales agents in over 10 countries. We are the only ingredient company to be awarded the Dun and Bradstreet's fastest growing company in America twice in 1999 and 2002. *"These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease."
© AHD International, LLC.
Legal and Privacy Statement |
|