Ads by Google
Chemical Name:L-Hydroxyproline
Molecular Formula :C5H9NO3
Molecular Weight 131.13
Characteristics
White flaky crystal or crystalline powder
Packing:25kg/drum,25kg/carton
pharmaceutical source/
Quality Standard: AJI92/USP28/EP5/FCCIV/
Specification:
Specific rotation[a]D 20 | -74.0---- -77.0 |
State pf Solution | 95PCT MIN |
Heavy metals(Pb) | 10PPM MAX |
Residue on ignition(Sulfated) | 0.1PCT MAX |
Iron(Fe) | 10PPM MAX |
Loss on Drying | 0.02PCT MAX |
Other amino Acid | Conforms |
As(As2O3)(Sulfated) | 1 PPM MAX |
Chloride(CI) | 0.002PCT MAX |
Ammonium(NH4) | 0.02PCT MAX |
Sulfate(SO4) | 98.5PCT --101PCT |
Assay | 99PCT--101PCT |
PH | 5.0--6.5 |
Usage:
Amino Acid Food Additive L-Hydroxyprolin
1.Flavor enhancers; nutritional enhancer and flavoring 2.For antibiotics and anti-tumor, anti-high blood pressure
Hydroxyproline is produced by hydroxylation of the amino acid proline by the enzyme prolyl hydroxylase following protein synthesis (as a post-translational modification). The enzyme catalysed reaction takes place in the lumen of the endoplasmic reticulum. Although it is not directly incorporated into proteins, hydroxyproline comprises roughly 4% of all amino acids found in animal tissue, more than seven amino acids which are directly incorporated.[2]
Hydroxyproline is a major component of the protein collagen[3]. Hydroxyproline and proline play key roles for collagen stability.[4] They permit the sharp twisting of the collagen helix.[5] In the canonical collagen Xaa-Yaa-Gly triad (where Xaa and Yaa are any amino acid), a proline occupying the Yaa position is hydroxylated to give a Xaa-Hyp-Gly sequence. This modification of the proline residue increases the stability of the collagen triple helix. It was initially proposed that the stabilization was due to water molecules forming a hydrogen bonding network linking the prolyl hydroxyl groups and the main-chain carbonyl groups.[6] It was subsequently shown that the increase in stability is primarily through stereoelectronic effects and that hydration of the hydroxyproline residues provides little or no additional stability.[7] In addition to collagen, the mammalian proteins elastin and argonaute 2 have collagen-like domains in which hydroxyproline is formed. Some snail poisons, conotoxins, contain hydroxyproline, but lack collagen-like sequences.
Hydroxylation of proline has been shown to be involved in targeting Hypoxia-inducible factor (HIF) alpha subunit (HIF-1 alpha) for degradation by proteolysis. Under normoxia (normal oxygen conditions) EGLN1[1] protein hydroxylates the proline at the 564 position of HIF-1 alpha, which allows ubiquitylation by the von Hippel-Lindau tumor suppressor (pVHL) and subsequent targeting for proteasome degradation.[8]
Hydroxyproline is found in few proteins other than collagen. For this reason, hydroxyproline content has been used as an indicator to determine collagen and/or gelatin amount.
Hydroxyproline rich glycoproteins are also found in plant cell walls.
Proline hydroxylation requires ascorbic acid (vitamin C). The most obvious, first effects (gingival and hair problems) of absence of ascorbic acid in humans come from the resulting defect in hydroxylation of proline residues of collagen
L-Hydroxyproline food grade