scholarly journals Pentosan polysulfate increases affinity between ADAMTS-5 and TIMP-3 through formation of an electrostatically driven trimolecular complex

2012 ◽  
Vol 443 (1) ◽  
pp. 307-315 ◽  
Author(s):  
Linda Troeberg ◽  
Barbara Mulloy ◽  
Peter Ghosh ◽  
Meng-Huee Lee ◽  
Gillian Murphy ◽  
...  
Keyword(s):  
Sulfated Polysaccharide ◽  
Pentosan Polysulfate ◽  
Endogenous Inhibitor ◽  
Binding Ability ◽  
Physiological Conditions ◽  
Interaction Sites ◽  
High Affinity ◽  
Multiple Protein ◽  
Trimolecular Complex ◽  
Protein Interaction Sites

The semi-synthetic sulfated polysaccharide PPS (pentosan polysulfate) increases affinity between the aggrecan-degrading ADAMTSs (adamalysins with thrombospondin motifs) and their endogenous inhibitor, TIMP (tissue inhibitor of metalloproteinases)-3. In the present study we demonstrate that PPS mediates the formation of a high-affinity trimolecular complex with ADAMTS-5 and TIMP-3. A TIMP-3 mutant that lacks extracellular-matrix-binding ability was insensitive to this affinity increase, and truncated forms of ADAMTS-5 that lack the Sp (spacer) domain had reduced PPS-binding ability and sensitivity to the affinity increase. PPS molecules composed of 11 or more saccharide units were 100-fold more effective than those of eight saccharide units, indicating the involvement of extended or multiple protein-interaction sites. The formation of a high-affinity trimolecular complex was completely abolished in the presence of 0.4 M NaCl. These results suggest that PPS enhances the affinity between ADAMTS-5 and TIMP-3 by forming electrostatically driven trimolecular complexes under physiological conditions.

Conformation as the Therapeutic Target for Neurodegenerative Diseases

2017 ◽  
Vol 14 (4) ◽  
pp. 393-402 ◽  
Author(s):  
Rajaraman Krishnan ◽  
Franz Hefti ◽  
Haim Tsubery ◽  
Michal Lulu ◽  
Ming Proschitsky ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Neurodegenerative Diseases ◽  
Protein Misfolding ◽  
Specific Binding ◽  
Drug Candidate ◽  
High Affinity ◽  
Novel Approach ◽  
Multiple Protein ◽  
Clinical Benefits ◽  
Effective Drugs

Therapeutic strategies that target pathways of protein misfolding and the toxicity of intermediates along these pathways are mainly at discovery and early development stages, with the exception of monoclonal antibodies that have mainly failed to produce convincing clinical benefits in late stage trials. The clinical failures represent potentially critical lessons for future neurodegenerative disease drug development. More effective drugs may be achieved by pursuing the following two strategies. First, conformational targeting of aggregates of misfolded proteins, rather than less specific binding that includes monomer subunits, which vastly outnumber the toxic targets. Second, since neurodegenerative diseases frequently include more than one potential protein pathology, generic targeting of aggregates by shape might also be a crucial feature of a drug candidate. Incorporating both of these critical features into a viable drug candidate along with high affinity binding has not been achieved with small molecule approaches or with antibody fragments. Monoclonal antibodies developed so far are not broadly acting through conformational recognition. Using GAIM (General Amyloid Interaction Motif) represents a novel approach that incorporates high affinity conformational recognition for multiple protein assemblies, as well as recognition of an array of assemblies along the misfolding pathway between oligomers and fibers. A GAIM-Ig fusion, NPT088, is nearing clinical testing.

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