Angiopoietin-2 aptamer



Description

Sullenger, B. A. et al. reported aptamers with affinity for angiopoietin-2 in their article published in 2003. The 11-1.41 aptamer was named by Sullenger, B. A. et al. in the article[1].



SELEX

In their work published in 2003, Sullenger, B. A. et al. used SELEX to isolate RNA aptamer sequences with affinity for angiopoietin-2 from a nucleic acid library containing about 1014 80-nucleotides-long sequences after 11 rounds of selection process. RNAs bound to Ang2 were isolated via vacuum filtration through a 0.45 μm nitrocellulose membrane[1].

Detailed information are accessible on SELEX page.



Structure

The 2D structure of the figure is based on the article by online secondary structure prediction tool to draw. The figure shows the secondary structure prediction of the original aptamer sequence. This aptamer consists of a stem loop containing 3 bulges and 2 G-U non-canonical base pairings[1].

5'-GAGGACGAUGCGGACUAGCCUCAUACUCCGAUGUGCCCCUC-3'

drawing


Ligand information

SELEX ligand

Angiopoietin-2 binds to TEK/TIE2, competing for the ANGPT1 binding site, and modulating ANGPT1 signaling. Can induce tyrosine phosphorylation of TEK/TIE2 in the absence of ANGPT1. In the absence of angiogenic inducers, such as VEGF, ANGPT2-mediated loosening of cell-matrix contacts may induce endothelial cell apoptosis with consequent vascular regression. In concert with VEGF, it may facilitate endothelial cell migration and proliferation, thus serving as a permissive angiogenic signal.-----From Uniprot

UniProt ID: uniquely identifies protein sequences in the UniProt database, a resource for protein information.

Pfam: a widely recognised database of protein families and domains.

GenBank: maintained by NCBI(National Center for Biotechnology Information), is a database of nucleotide sequences from various organisms, vital for genetic and molecular biology research.

Mass: an intrinsic property of a body.

Name Uniprot ID Pfam Mass Protein sequence PDB ID GenBank
Ang2 (Angiopoietin-2) O15123 PF00147 56.919 kDa
...... MWQIVFFTLSCDLVLAAAYNNFRKSMDSIGKKQYQVQHGSCSYTFLLPEMDNCRSSSSPYVSNAVQRDAPLEYDDSVQRLQVLENIMENNTQWLMKLENYIQDNMKKEMVEIQQNAVQNQTAVMIEIGTNLLNQTAEQTRKLTDVEAQVLNQTTRLELQLLEHSLSTNKLEKQILDQTSEINKLQDKNSFLEKKVLAMEDKHIIQLQSIKEEKDQLQVLVSKQNSIIEELEKKIVTATVNNSVLQKQQHDLMETVNNLLTMMSTSNSAKDPTVAKEEQISFRDCAEVFKSGHTTNGIYTLTFPNSTEEIKAYCDMEAGGGGWTIIQRREDGSVDFQRTWKEYKVGFGNPSGEYWLGNEFVSQLTNQQRYVLKIHLKDWEGNEAYSLYEHFYLSSEELNYRIHLKGLTGTAGKISSISQPGNDFSTKDGDNDKCICKCSQMLTGGWWFDACGPSNLNGMYYPQRQNTNKFNGIKWYYWKGSGYSLKATTMMIRPADF
2GY7 285

Some isolated sequences bind to the affinity of the protein[1].

Name Sequence Ligand Affinity
11-1.41 aptamer 5'-GAGGACGAUGCGGACUAGCCUCAUACUCCGAUGUGCCCCUC-3' Angiopoietin-2 2.2 nM
11-1 aptamer 5'-GGGAGGACGATGCGGACUAGCCUCAUCAGCUCAUGUGCCCCUCCGCCUGGAUCACCAGACGACTCGCTGAGGATCCGAGA-3' Angiopoietin-2 3.1 nM
drawing

Similar compound(s)

We used the Dail server website to compare the structural similarities of ligand proteins, and chose the top 10 in terms of similarity for presentation.

Dail server website: a network service for comparing protein structures in 3D. Dali compares them against those in the Protein Data Bank (PDB).

Z-score: a standard score that is converted from an original score. The list of neighbours is sorted by Z-score. Similarities with a Z-score lower than 2 are spurious.

RMSD: (Root Mean Square Deviation) is used to measure the degree to which atoms deviate from the alignment position.

PDB: PDB ID+ chain name.

PDB Z-socre RMSD Description
2GY7-A 43.7 0 Original chain
4K0V-A 57.5 0.9 Tek tyrosine kinase variant
2V5Y-A 10.2 13.2 Receptor-type tyrosine-protein phosphatase Mu
2ID5-B 9.8 11.0 Leucine rich repeat neuronal 6A
3TF7-C 9.5 6.7 H2-ld SBM2
8BXR-A 9.5 2.1 Ritin
6RUL-A 9.4 1.9 GFP-lama-F98 a GFP enhancer nanobody with Cpdhfr
3B43-A 9.3 17.6 Titin
8ES7-B 9.1 9.3 T-cell surface glycoprotein Cd3 zeta chain
8ES8-A 9.1 3.9 T-cell surface glycoprotein Cd3 zeta chain
3SO5-B 9.1 2.6 Leucine-rich repeats and immunoglobulin-like doma


References

[1] Inhibition of rat corneal angiogenesis by a nuclease-resistant RNA aptamer specific for angiopoietin-2.
White, R. R., Shan, S., Rusconi, C. P., Shetty, G., Dewhirst, M. W., Kontos, C. D., & Sullenger, B. A.
Proceedings of the National Academy of Sciences of the United States of America, 100(9), 5028–5033. (2003)