The amino acids Gly and Pro, as well as modified prolines th…
The amino acids Gly and Pro, as well as modified prolines that have a hydroxy group on the Pro ring or Hyp, are the principal amino acids comprising collagen. Consider this excerpt from this article: Destabilization of osteogenesis imperfecta collagen-like model peptides correlates with the identity of the residue replacing glycineKonrad Beck, Virginia C. Chan, Nigel Shenoy, Alan Kirkpatrick, John A. M. Ramshaw, and Barbara BrodskyPNAS April 11, 2000 97 (8) 4273-4278; https://doi.org/10.1073/pnas.070050097 “Gly-Pro-Hyp is the most common, as well as the most stabilizing, triplet in collagen (5). The presence of Gly at every third residue is considered essential….” If there is a genetic mutation that interrupts this pattern of Gly at every third position, bones do not develop properly. They are characteristically brittle, resulting in a genetic disease known as osteogenesis imperfecta. Use your knowledge of the structure of collagen to explain why this regularly repeating Gly residue is essential to the formation of a proper and strong collagen triple helix? (2 pts.) Vitamin C is required for the biochemical reaction that puts the modifying OH group on a Pro in collagen. Why does a vitamin C deficiency result in changing the overall strength of collagen? (2 pts.)
Read DetailsV-8 peptidase is an endopeptidase isolated from a strain of …
V-8 peptidase is an endopeptidase isolated from a strain of Staph. Aureus that cleaves a peptide bond on the carboxy side of acidic residuesin 50mM ammonium carbonate buffer at pH 8 . Treatment of peptides similar to the rattlesnake peptide with V-8 peptidase proceeds slowly, taking about 24 h to completely cleave or cut the peptide. However, if dithiothreitol (DTT) is added to the reaction in a 20 fold molar excess or BME (
Read DetailsIsoelectric focusing gel electrophoresis separates non-denat…
Isoelectric focusing gel electrophoresis separates non-denatured proteins and peptides by their isoelectric points using a pH gradient gel. Would you predict that this peptide would stop its travel through the gel in the acidic or basic portion of the gel? Briefly justify your choice.
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