Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:Q86TM3 (cage)
 29,987 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Specific human antibodies targeting proteases expressed on cancer cells can be valuable reagents for diagnosis, prognosis, and therapy of cancer. To this end, a phage-displayed antibody library was screened against a cancer-associated serine protease, MT-SP1. A protein inhibitor of serine proteases that binds to a defined surface of MT-SP1 was used in an affinity-based washing procedure. Six antibodies were selected on the basis of their ELISA profiles and ability to serve as useful immunological reagents. The apparent K(i), indicative of the potency of the antibodies at inhibiting human MT-SP1 activity, ranged from 50 pM to 129 nM. Two of the antibodies had approximately 800-fold and 1500-fold selectivity when tested against the most homologous serine protease family member, mouse MT-SP1, that exhibits 86.6% sequence identity. Surface plasmon resonance was used as an independent means of determining the binding constants of the six antibodies. Association rates were as high as 1.15 x 10(7) s(-)(1) M(-)(1), and dissociation rates were as low as 3.8 x 10(-)(4) s(-)(1). One antibody was shown to detect denatured MT-SP1 with no cross reactivity to other family members in HeLa or PC3 cells. Another antibody recognized the enzyme in human prostate tissue samples for immunohistochemistry analysis. The mode of binding among the six antibodies and the protease was analyzed by competition ELISA using three distinctly different inhibitors that mapped the enzyme surface. These antibodies constitute a new class of highly selective protease inhibitors that can be used to dissect the biological roles of proteolytic enzymes as well as to develop diagnostic and therapeutic reagents.
 ...
PMID:Potent and selective inhibition of membrane-type serine protease 1 by human single-chain antibodies. 1254 7

The high degree of specificity displayed by antibodies often results in varying potencies against antigen orthologs, which can affect the efficacy of these molecules in different animal models of disease. We have used a computational design strategy to improve the species cross-reactivity of an antibody-based inhibitor of the cancer-associated serine protease MT-SP1. In silico predictions were tested in vitro, and the most effective mutation, T98R, was shown to improve antibody affinity for the mouse ortholog of the enzyme 14-fold, resulting in an inhibitor with a K(I) of 340 pM. This improved affinity will be valuable when exploring the role of MT-SP1 in mouse models of cancer, and the strategy outlined here could be useful in fine-tuning antibody specificity.
 ...
PMID:Improving the species cross-reactivity of an antibody using computational design. 1947 27