CRYSTAL STRUCTURE OF THE TUMOR SPECIFIC ANTIBODY SM3 COMPLEX WITH ITS PEPTIDE EPITOPECRYSTAL STRUCTURE OF THE TUMOR SPECIFIC ANTIBODY SM3 COMPLEX WITH ITS PEPTIDE EPITOPE
Structural highlights
1sm3 is a 3 chain structure with sequence from Homo sapiens and Mus musculus. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance.
MUC1_HUMAN Note=MUC1/CA 15-3 is used as a serological clinical marker of breast cancer to monitor response to breast cancer treatment and disease recurrence (PubMed:20816948). Decreased levels over time may be indicative of a positive response to treatment. Conversely, increased levels may indicate disease progression. At an early stage disease, only 21% of patients exhibit high MUC1/CA 15-3 levels, that is why CA 15-3 is not a useful screening test. Most antibodies target the highly immunodominant core peptide domain of 20 amino acid (APDTRPAPGSTAPPAHGVTS) tandem repeats. Some antibodies recognize glycosylated epitopes.
Function
MUC1_HUMAN The alpha subunit has cell adhesive properties. Can act both as an adhesion and an anti-adhesion protein. May provide a protective layer on epithelial cells against bacterial and enzyme attack.[1][2][3][4][5][6][7][8][9] The beta subunit contains a C-terminal domain which is involved in cell signaling, through phosphorylations and protein-protein interactions. Modulates signaling in ERK, SRC and NF-kappa-B pathways. In activated T-cells, influences directly or indirectly the Ras/MAPK pathway. Promotes tumor progression. Regulates TP53-mediated transcription and determines cell fate in the genotoxic stress response. Binds, together with KLF4, the PE21 promoter element of TP53 and represses TP53 activity.[10][11][12][13][14][15][16][17][18]
Evolutionary Conservation
Check, as determined by ConSurfDB. You may read the explanation of the method and the full data available from ConSurf.
Publication Abstract from PubMed
The anti-breast tumour antibody SM3 has a high selectivity in reacting specifically with carcinoma-associated mucin. SM3 recognises the core repeating motif (Pro-Asp-Thr-Arg-Pro) of aberrantly glycosylated epithelial mucin MUC1, and has potential as a therapeutic and diagnostic tool. Here we report the crystal structure of the Fab fragment of SM3 in complex with a 13-residue MUC1 peptide antigen (Thr1P-Ser2P-Ala3P-Pro4P-Asp5P-Thr6P -Arg7P-Pro8P-Ala9P-Pro10P-Gly11P- Ser12P-Thr13P). The SM3-MUC1 peptide structure was solved by molecular replacement, and the current model is refined at 1.95 A resolution with an R-factor of 21.3% and R-free 28.3%. The MUC1 peptide is bound both by non-polar interactions and hydrogen bonds in an elongated groove in the antibody-combining site through interactions with Complimentarity Determining Regions (CDRs), three of the light chain (L1, L2, L3) and two of the heavy chain (H1 and H3). The conformation of the peptide is mainly extended with no discernable standard secondary structure. There is a single non-proline cis-peptide bond in H3 (Val95H-Gly96H-Gln97H-Phe98H-Ala101H-Ty r102H) between Gly96H and Gln97H, which appears to play a role in SM3-peptide antigen interactions, and represents the first such example within an antibody hypervariable loop. The SM3-MUC1 peptide structure has implications for rational therapeutic and diagnostic antibody engineering.
Crystal structure at 1.95 A resolution of the breast tumour-specific antibody SM3 complexed with its peptide epitope reveals novel hypervariable loop recognition.,Dokurno P, Bates PA, Band HA, Stewart LM, Lally JM, Burchell JM, Taylor-Papadimitriou J, Snary D, Sternberg MJ, Freemont PS J Mol Biol. 1998 Dec 4;284(3):713-28. PMID:9826510[19]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑Yamamoto M, Bharti A, Li Y, Kufe D. Interaction of the DF3/MUC1 breast carcinoma-associated antigen and beta-catenin in cell adhesion. J Biol Chem. 1997 May 9;272(19):12492-4. PMID:9139698
↑Ren J, Li Y, Kufe D. Protein kinase C delta regulates function of the DF3/MUC1 carcinoma antigen in beta-catenin signaling. J Biol Chem. 2002 May 17;277(20):17616-22. Epub 2002 Mar 4. PMID:11877440 doi:10.1074/jbc.M200436200
↑Huang L, Ren J, Chen D, Li Y, Kharbanda S, Kufe D. MUC1 cytoplasmic domain coactivates Wnt target gene transcription and confers transformation. Cancer Biol Ther. 2003 Nov-Dec;2(6):702-6. PMID:14688481
↑Wei X, Xu H, Kufe D. Human MUC1 oncoprotein regulates p53-responsive gene transcription in the genotoxic stress response. Cancer Cell. 2005 Feb;7(2):167-78. PMID:15710329 doi:10.1016/j.ccr.2005.01.008
↑Huang L, Chen D, Liu D, Yin L, Kharbanda S, Kufe D. MUC1 oncoprotein blocks glycogen synthase kinase 3beta-mediated phosphorylation and degradation of beta-catenin. Cancer Res. 2005 Nov 15;65(22):10413-22. PMID:16288032 doi:65/22/10413
↑Mukherjee P, Tinder TL, Basu GD, Gendler SJ. MUC1 (CD227) interacts with lck tyrosine kinase in Jurkat lymphoma cells and normal T cells. J Leukoc Biol. 2005 Jan;77(1):90-9. Epub 2004 Oct 28. PMID:15513966 doi:jlb.0604333
↑Lillehoj EP, Lu W, Kiser T, Goldblum SE, Kim KC. MUC1 inhibits cell proliferation by a beta-catenin-dependent mechanism. Biochim Biophys Acta. 2007 Jul;1773(7):1028-38. Epub 2007 Apr 22. PMID:17524503 doi:S0167-4889(07)00092-4
↑Wei X, Xu H, Kufe D. Human mucin 1 oncoprotein represses transcription of the p53 tumor suppressor gene. Cancer Res. 2007 Feb 15;67(4):1853-8. PMID:17308127 doi:67/4/1853
↑Pochampalli MR, el Bejjani RM, Schroeder JA. MUC1 is a novel regulator of ErbB1 receptor trafficking. Oncogene. 2007 Mar 15;26(12):1693-701. Epub 2006 Sep 18. PMID:16983337 doi:1209976
↑Yamamoto M, Bharti A, Li Y, Kufe D. Interaction of the DF3/MUC1 breast carcinoma-associated antigen and beta-catenin in cell adhesion. J Biol Chem. 1997 May 9;272(19):12492-4. PMID:9139698
↑Ren J, Li Y, Kufe D. Protein kinase C delta regulates function of the DF3/MUC1 carcinoma antigen in beta-catenin signaling. J Biol Chem. 2002 May 17;277(20):17616-22. Epub 2002 Mar 4. PMID:11877440 doi:10.1074/jbc.M200436200
↑Huang L, Ren J, Chen D, Li Y, Kharbanda S, Kufe D. MUC1 cytoplasmic domain coactivates Wnt target gene transcription and confers transformation. Cancer Biol Ther. 2003 Nov-Dec;2(6):702-6. PMID:14688481
↑Wei X, Xu H, Kufe D. Human MUC1 oncoprotein regulates p53-responsive gene transcription in the genotoxic stress response. Cancer Cell. 2005 Feb;7(2):167-78. PMID:15710329 doi:10.1016/j.ccr.2005.01.008
↑Huang L, Chen D, Liu D, Yin L, Kharbanda S, Kufe D. MUC1 oncoprotein blocks glycogen synthase kinase 3beta-mediated phosphorylation and degradation of beta-catenin. Cancer Res. 2005 Nov 15;65(22):10413-22. PMID:16288032 doi:65/22/10413
↑Mukherjee P, Tinder TL, Basu GD, Gendler SJ. MUC1 (CD227) interacts with lck tyrosine kinase in Jurkat lymphoma cells and normal T cells. J Leukoc Biol. 2005 Jan;77(1):90-9. Epub 2004 Oct 28. PMID:15513966 doi:jlb.0604333
↑Lillehoj EP, Lu W, Kiser T, Goldblum SE, Kim KC. MUC1 inhibits cell proliferation by a beta-catenin-dependent mechanism. Biochim Biophys Acta. 2007 Jul;1773(7):1028-38. Epub 2007 Apr 22. PMID:17524503 doi:S0167-4889(07)00092-4
↑Wei X, Xu H, Kufe D. Human mucin 1 oncoprotein represses transcription of the p53 tumor suppressor gene. Cancer Res. 2007 Feb 15;67(4):1853-8. PMID:17308127 doi:67/4/1853
↑Pochampalli MR, el Bejjani RM, Schroeder JA. MUC1 is a novel regulator of ErbB1 receptor trafficking. Oncogene. 2007 Mar 15;26(12):1693-701. Epub 2006 Sep 18. PMID:16983337 doi:1209976
↑Dokurno P, Bates PA, Band HA, Stewart LM, Lally JM, Burchell JM, Taylor-Papadimitriou J, Snary D, Sternberg MJ, Freemont PS. Crystal structure at 1.95 A resolution of the breast tumour-specific antibody SM3 complexed with its peptide epitope reveals novel hypervariable loop recognition. J Mol Biol. 1998 Dec 4;284(3):713-28. PMID:9826510 doi:10.1006/jmbi.1998.2209