H-Ala-Pro-Asp-Thr(Neu5Acα2->3Galβ1->3GalNAcα)-Arg-Pro-Ala-Pro-Gly-Ser-Thr-Ala-Pro-Pro-Ala-NH2 | 1194535-47-1

• 分子结构分类: 有机化合物 - 有机聚合物 - 多肽
• 英文名称: H-Ala-Pro-Asp-Thr(Neu5Acα2->3Galβ1->3GalNAcα)-Arg-Pro-Ala-Pro-Gly-Ser-Thr-Ala-Pro-Pro-Ala-NH2
• 英文别名: (2S,4S,5R,6R)-5-acetamido-2-[(2R,3R,4S,5S,6R)-2-[(2S,3R,4R,5R,6R)-3-acetamido-2-[(2R,3S)-4-[[(2S)-1-[(2S)-2-[[(2S)-1-[(2S)-2-[[2-[[(2S)-1-[[(2S,3R)-1-[[(2S)-1-[(2S)-2-[(2S)-2-[[(2S)-1-amino-1-oxopropan-2-yl]carbamoyl]pyrrolidine-1-carbonyl]pyrrolidin-1-yl]-1-oxopropan-2-yl]amino]-3-hydroxy-1-oxobutan-2-yl]amino]-3-hydroxy-1-oxopropan-2-yl]amino]-2-oxoethyl]carbamoyl]pyrrolidin-1-yl]-1-oxopropan-2-yl]carbamoyl]pyrrolidin-1-yl]-5-(diaminomethylideneamino)-1-oxopentan-2-yl]amino]-3-[[(2S)-2-[[(2S)-1-[(2S)-2-aminopropanoyl]pyrrolidine-2-carbonyl]amino]-3-carboxypropanoyl]amino]-4-oxobutan-2-yl]oxy-5-hydroxy-6-(hydroxymethyl)oxan-4-yl]oxy-3,5-dihydroxy-6-(hydroxymethyl)oxan-4-yl]oxy-4-hydroxy-6-[(1R,2R)-1,2,3-trihydroxypropyl]oxane-2-carboxylic acid
• CAS: 1194535-47-1
• 化学式: C₈₅H₁₃₇N₂₁O₃₈
• 分子量: 2061.14
• InChiKey: GRXSUAYRLRMYOD-SHRLZOCDSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -16.1
• 重原子数：
  144
• 可旋转键数：
  47
• 环数：
  8.0
• sp3杂化的碳原子比例：
  0.76
• 拓扑面积：
  908
• 氢给体数：
  28
• 氢受体数：
  40

反应信息

• 作为产物：
  描述：

  H-Ala-Pro-Asp-Thr(Galβ1->3GalNAcα)-Arg-Pro-Ala-Pro-Gly-Ser-Thr-Ala-Pro-Pro-Ala-NH2 、 CMP-sialic acid 在 α2,3-(O)-sialyltransferase 作用下， 反应 24.0h， 以100%的产率得到H-Ala-Pro-Asp-Thr(Neu5Acα2->3Galβ1->3GalNAcα)-Arg-Pro-Ala-Pro-Gly-Ser-Thr-Ala-Pro-Pro-Ala-NH2
  参考文献：
  名称：

  An Essential Epitope of Anti-MUC1 Monoclonal Antibody KL-6 Revealed by Focused Glycopeptide Library

  摘要：

  Human serum Krebs von den Lungen-6 (KL-6) antigen, a high-molecular-weight glycoprotein classified as a polymorphic epithelial mucin (MUC1), is a biomarker of diseases such as interstitial pneumonia, lung adenocarcinoma, breast cancer, colorectal adenocarcinoma, and hepatocellular carcinoma. Anti-KL-6 monoclonal antibody (anti-KL-6 MAb) is therefore a potential diagnostic and therapeutic reagent. Although glycosylation at Thr/Ser residues of the tandem-repeating MUC1 peptides appears to determine the disease-associated antigenic structures of KL-6, an essential epitope structure recognized by anti-KL-6 MAb remains unclear. In the present study, a novel compound library of synthetic MUC1 glycopeptides allowed the first rapid and precise evaluation of the specific epitope structure of anti-KL-6 MAb by combined use of a tailored glycopeptides library and common ELISA protocol. We demonstrated that the minimal antigenic structure, an essential epitope, recognized by anti-KL-6 MAb is a heptapeptide sequence Pro-Asp-Thr-Arg-Pro-Ala-Pro (PDTRPAP), in which the Thr residue is modified by Neu5Ac alpha 2,3Gal beta 1,3GalNAc alpha (2,3-sialyl T antigen, core 1-type O-glycan). Anti-KL-6 MAb did not bind with other tumor-relevant antigens, such as GalNA alpha(Tn), Neu5Ac alpha 2,6GalNAc alpha(STn), and Gal beta 1,3GalNAc alpha (T), except for Neu5Ac alpha 2,3Gal beta 1,3(Neu5Ac alpha 2,6) GalNAc alpha(2,3/2,6-disialyl T). However, anti-KL-6 MAb could not differentiate the above minimal antigenic glycopepticle from some core 2-based glycopeptides involving this crucial epitope structure and showed a similar binding affinity toward these compounds, indicating that branching at the O-6 position of GalNAc residue does not influence the interaction of anti-KL-6 MAb with some MUC1 glycoproteins involving an essential epitope. Actually, anti-KL-6 MAb reacts with 2,3/2,6-disialyl T having a 2,3-sialyl T component. This is why anti-KL-6 MAb often reacts with various kinds of tumor-derived MUC1 glycoproteins as well as a clinically important MUC1 glycoprotein biomarker of interstitial pneumonia, namely KL-6, originally discovered as a circulating pulmonary adenocarcinoma-associated antigen. In other words, combined use of anti-KL-6 MAb and some probes that can differentiate the sugars substituted at the O-6 position of the GalNAc residue in MUC1 glycopeptides including the PDTRPAP sequence might be a promising diagnostic protocol for individual disease-specific biomarkers. It was also revealed that glycosylation at neighboring Thr/Ser residues outside the immunodominant PDTRPAP motif strongly influences the interaction between anti-KL-6 MAb and MUC1 glycopeptides involving the identified epitope. Our novel strategy will greatly facilitate the processes for the identification of the tumor-specific and strong epitopes of various known anti-MUC1 MAbs and allow for their practical application in the generation of improved antibody immunotherapeutics, diagnostics, and MUC1-based cancer vaccines.

  DOI：

  10.1021/ja903361f

文献信息

• An Essential Epitope of Anti-MUC1 Monoclonal Antibody KL-6 Revealed by Focused Glycopeptide Library
  作者：Naoki Ohyabu、Hiroshi Hinou、Takahiko Matsushita、Ryukou Izumi、Hiroki Shimizu、Keiko Kawamoto、Yoshito Numata、Hiroko Togame、Hiroshi Takemoto、Hirosato Kondo、Shin-Ichiro Nishimura

  DOI：10.1021/ja903361f

  日期：2009.12.2

  Human serum Krebs von den Lungen-6 (KL-6) antigen, a high-molecular-weight glycoprotein classified as a polymorphic epithelial mucin (MUC1), is a biomarker of diseases such as interstitial pneumonia, lung adenocarcinoma, breast cancer, colorectal adenocarcinoma, and hepatocellular carcinoma. Anti-KL-6 monoclonal antibody (anti-KL-6 MAb) is therefore a potential diagnostic and therapeutic reagent. Although glycosylation at Thr/Ser residues of the tandem-repeating MUC1 peptides appears to determine the disease-associated antigenic structures of KL-6, an essential epitope structure recognized by anti-KL-6 MAb remains unclear. In the present study, a novel compound library of synthetic MUC1 glycopeptides allowed the first rapid and precise evaluation of the specific epitope structure of anti-KL-6 MAb by combined use of a tailored glycopeptides library and common ELISA protocol. We demonstrated that the minimal antigenic structure, an essential epitope, recognized by anti-KL-6 MAb is a heptapeptide sequence Pro-Asp-Thr-Arg-Pro-Ala-Pro (PDTRPAP), in which the Thr residue is modified by Neu5Ac alpha 2,3Gal beta 1,3GalNAc alpha (2,3-sialyl T antigen, core 1-type O-glycan). Anti-KL-6 MAb did not bind with other tumor-relevant antigens, such as GalNA alpha(Tn), Neu5Ac alpha 2,6GalNAc alpha(STn), and Gal beta 1,3GalNAc alpha (T), except for Neu5Ac alpha 2,3Gal beta 1,3(Neu5Ac alpha 2,6) GalNAc alpha(2,3/2,6-disialyl T). However, anti-KL-6 MAb could not differentiate the above minimal antigenic glycopepticle from some core 2-based glycopeptides involving this crucial epitope structure and showed a similar binding affinity toward these compounds, indicating that branching at the O-6 position of GalNAc residue does not influence the interaction of anti-KL-6 MAb with some MUC1 glycoproteins involving an essential epitope. Actually, anti-KL-6 MAb reacts with 2,3/2,6-disialyl T having a 2,3-sialyl T component. This is why anti-KL-6 MAb often reacts with various kinds of tumor-derived MUC1 glycoproteins as well as a clinically important MUC1 glycoprotein biomarker of interstitial pneumonia, namely KL-6, originally discovered as a circulating pulmonary adenocarcinoma-associated antigen. In other words, combined use of anti-KL-6 MAb and some probes that can differentiate the sugars substituted at the O-6 position of the GalNAc residue in MUC1 glycopeptides including the PDTRPAP sequence might be a promising diagnostic protocol for individual disease-specific biomarkers. It was also revealed that glycosylation at neighboring Thr/Ser residues outside the immunodominant PDTRPAP motif strongly influences the interaction between anti-KL-6 MAb and MUC1 glycopeptides involving the identified epitope. Our novel strategy will greatly facilitate the processes for the identification of the tumor-specific and strong epitopes of various known anti-MUC1 MAbs and allow for their practical application in the generation of improved antibody immunotherapeutics, diagnostics, and MUC1-based cancer vaccines.