H-Leu-Thr-NH2*TFA | 75671-57-7

• 分子结构分类: 有机化合物 - 有机酸及其衍生物 - 羧酸及其衍生物
• 英文名称: H-Leu-Thr-NH2*TFA
• CAS: 75671-57-7
• 化学式: C₂HF₃O₂*C₁₀H₂₁N₃O₃
• 分子量: 345.319
• InChiKey: LKQXBLPZACLXPG-MWDCIYOWSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -0.66
• 重原子数：
  23.0
• 可旋转键数：
  6.0
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.75
• 拓扑面积：
  155.74
• 氢给体数：
  5.0
• 氢受体数：
  5.0

反应信息

• 作为反应物：
  描述：

  N-(叔丁氧羰基L)-S-甲基-L-半胱氨酸 、 H-Leu-Thr-NH2*TFA 在 N-甲基吗啉 、 1-羟基苯并三唑 、 盐酸-N-乙基-Nˊ-(3-二甲氨基丙基)碳二亚胺 作用下， 生成 tert-butyl N-[(2R)-1-[[(2S)-1-[[(2S,3R)-1-amino-3-hydroxy-1-oxobutan-2-yl]amino]-4-methyl-1-oxopentan-2-yl]amino]-3-methylsulfanyl-1-oxopropan-2-yl]carbamate
  参考文献：
  名称：

  Synthesis and Evaluation of Tripeptides Containing Asparagine Analogues as Potential Substrates or Inhibitors of Oligosaccharyltransferase

  摘要：

  The amino acids 5-diazo-4-oxo-L-norvaline, 4-oxo-L-norvaline, and (methanesulfinyl)-L-alanine have been incorporated into three separate tripeptides wherein these nonnatural amino acids replace Asn in a known tripeptide substrate of oligosaccharyltransferase. Synthesis of both the diazoketone- and sulfoxide-containing peptides involved functionalization of the appropriate side chain after peptide assembly, whereas synthesis of the methyl ketone-containing peptide was effected by synthesis of the protected amino acid followed by its incorporation into the desired tripeptide. None of the three synthetic tripeptides showed activity as substrates, nor were they potent inhibitors of oligosaccharyltransferase at concentrations that were 10-35 times the K-m for the corresponding Asn-containing tripeptide substrate. NMR analysis in DMSO-d(6) showed that the diazoketone and methyl ketone peptides adopt the "Asx-turn" conformation, which has been postulated to be crucial for substrate binding. Furthermore, a nonsubstrate peptide, Ac-Asn-Pro-Thr-NH2, was found to adopt the "Asx-turn" in both the solid state and in solution(DMSO-d(6)). The collective data suggest that the ability to form an Asx-turn in the N-glycosylation consensus sequence (Asn-Xaa-Ser/Thr) may be a necessary but not sufficient condition for substrate binding and catalysis.

  DOI：

  10.1021/jo9802123

文献信息

• Yeast oligosaccharyltransferase: glycosylation of peptide substrates and chemical characterization of the glycopeptide product
  作者：Richard S. Clark、Shyamal Banerjee、James K. Coward

  DOI：10.1021/jo00313a013

  日期：1990.12

  The product of the reaction catalyzed by yeast oligosaccharyltransferase was examined in order to determine the nature of the chemical linkage between the sugar and peptide. Biosynthetic donor lipid [H-3]oligosaccharide was prepared and used as a substrate for yeast oligosaccharyltransferase together with a chemically synthesized peptide acceptor, N-benzoyl-Asn-Leu-Thr-NH2. the glycosylated peptide product of the in vitro reaction was isolated and hydrolyzed with endo-beta-N-acetylglucosaminidase-H to yield a large oligosaccharide and the glycotripeptide, N-benzoyl-Asn(GlcNAc)-Leu-Thr-Nh2. This glycopeptide was purified using gel filtration, affinity binding, and reverse-phase high-performance liquid chromatography. The biosynthetic glycopeptide was compared with chemically synthesized glycopeptides in which a 1-amino-GlcNAc moiety was linked to either the alpha- or beta-carboxyl of aspartate. It was determined that the sole biosynthetic product has the structure in which the carbohydrate is linked to the peptide through the beta-carbonyl of asparagine, i.e., a normal alpha-peptide. These experiments provide an unambiguous structural proof of the protein-carbohydrate linkage in the glycoprotein product of the oligosaccharyltransferase-catalyzed reaction.
• Enzyme-catalyzed glycosylation of peptides using a synthetic lipid disaccharide substrate
  作者：Jung Lee、James K. Coward

  DOI：10.1021/jo00041a015

  日期：1992.7

  A lipid disaccharide, consisting of chitobiose linked to dilichol via an alpha-1-pyrophosphate, has been synthesized for use as a substrate in the enzyme-catalyzed glycosylation of peptides. For the purpose of confirming the structure of the reaction product, the expected glycopeptide was synthesized via an unambiguous, convergent method. Chromatographic and spectral comparison of the synthetic vs biosynthetic glycopeptides showed that they were identical. Thus, glycosylation of synthetic peptides by a synthetically accessible lipid disaccharide can be effected using oligosaccharyltransferase isolated from yeast.