Collagen Structure Primary sequence GlyXProHy Pro Monomer alpha

Collagen Structure: Primary sequence : Gly-X-Pro(Hy. Pro) Monomer( alpha chain)=> left handed helix, 3 a. a. per turn Trimer: coiled-coil => stabilized by H-bond crosslink between triple helixes(disulfide bond) Tendons, cartilage, cornea, skin, bone Function: Provide tensile strength

Collagen Art(世界奇觀…. . )

The increasingly rigid and brittle charater of aging connective tissue results from accumulated covalent cross-links in fibrils

Covalent Cross-Links 共價連接 Tropocollagen結合成collagen之微纖維 (microfibril) ，最初是藉鏈內的氫鍵在穩定， 後來則靠螺旋內和螺旋間形成的共價鍵來穩 定。 Lysine lysyl oxidase Hydroxylysine aldehyde 上的ε胺基 醛纇

Ehlers-Danlos syndrome o o Ehlers-Danlos syndrome (EDS) refers to a group of inherited disorders that affect your connective tissues — primarily your skin, joints and blood vessel walls. 一般症狀 Loose, unstable joints Highly elastic, velvety skin

Causes o o A variety of genetic alterations (mutations) 遺傳方式：顯性遺傳、隱性遺傳、性聯遺傳 突變的基因無法正常合成下列蛋白質： Proteins that are used to assemble different types of collagen. Proteins that process or interact with collagen.

Scurvy(壞血病) symotioms oblood vessels ruptured and blood wept from hair follicles. o. Blotches appeared all over the body obruise or exertion could result in internal bleeding. o. Arms and legs would swell up owounds, even small scratches, would not heal. o. Gums reddened, receded, and blackened until teeth loosened and fell out 病因 o. The role that Vit. C plays in the formation of ligand. o. A collagen is constructed by many tripeptides. Gly-X-Y o. And the most stable form is Gly-Pro-4 -Hyp.

# The proline ring is normally found as a mixture of the two puckered conformation. # Cr-endo (Pro residue in the X position requires the Cr-endo conformation, and introduction of 4 -Hyp can destabilized the helix. ) # Cr-exo (The Y positions are in the Cr-exo conformation, and it’s this conformation that is enforced by the hydroxyl substitution at C-4 in 4 -hydroxyproline ) # The inability to hydroxylate the Pro at Y positions when Vit. C absent leads to collagen instability and the connective tissue problems seen in scurvy.

o o Prolyl hydroxylase is an enzyme involved in the production of collagen, acting to hydroxylate proline to hydroxyproline(Hyp). It requires vitamin C(ascorbic acid) as a co-factor. The process requires ascorbic acid as a reductant to restore enzyme activity. •