Characteristics of dimeric (bis) bidentate selective high affinity ligands as HLA-DR10 beta antibody mimics targeting non-Hodgkin's lymphoma.

Despite their large size, antibodies have proven to be suitable radioisotope carriers to deliver systemic radiotherapy, often molecular image-based, for lymphoma and leukemia. To mimic antibody (Ab) targeting behavior while decreasing size by 50-100x, a combination of computational and experimental methods were used to generate molecules that bind to unique sites within the HLA-DR epitopic region of Lym-1, an Ab shown effective in patients. Lym-1 Ab mimics (synthetic high afinity ligands; SHALs) were generated and studied in vitro, using live cell binding assays, and/or pharmacokinetic studies over 24 h in xenografted mice given 1 or 20 microg SHAL doses i.

Pharmacokinetic characterization in xenografted mice of a series of first-generation mimics for HLA-DR antibody, Lym-1, as carrier molecules to image and treat lymphoma.

Unlabelled: Despite their large size, antibodies (Abs) are suitable carriers to deliver systemic radiotherapy, often molecular image-based, for lymphoma and leukemia. Lym-1 Ab has proven to be an effective radioisotope carrier, even in small amounts, for targeting human leukocyte antigen DR (HLA-DR), a surface membrane protein overexpressed on B-cell lymphoma. Pairs of molecules (referred to as ligands), shown by computational and experimental methods to bind to each of 2 sites within the Lym-1 epitopic region, have been linked to generate small (<2 kDa) molecules (referred to as selective high-affinity ligands [SHALs]) to mimic the targeting properties of Lym-1 Ab.

Direct antilymphoma activity of novel, first-generation "antibody mimics" that bind HLA-DR10-positive non-Hodgkin's lymphoma cells.

A first-generation series of novel small molecules, collectively known as selective high-affinity ligands (SHALs), were designed and synthesized to mimic the binding of Lym-1, a monoclonal antibody (mAb) shown to be an effective cytotoxic and radionuclide carrier molecule for targeting non-Hodgkin's lymphoma (NHL). Created as radionuclide targeting molecules, these SHALs were intended to have the human leukocyte antigen-DR (HLA-DR) selectivity of Lym-1 mAb and the pharmacokinetics of a small molecule. Because of the remarkable bioactivity of Lym-1 in vitro, the direct antilymphoma activity of three of these SHALs was tested.

Nonlinearly additive forces in multivalent ligand binding to a single protein revealed with force spectroscopy.

We present evidence of multivalent interactions between a single protein molecule and multiple carbohydrates at a pH where the protein can bind four ligands. The evidence is based not only on measurements of the force required to rupture the bonds formed between concanavalin A (ConA) and alpha-D-mannose but also on an analysis of the polymer-extension force curves to infer the polymer architecture that binds the protein to the cantilever and the ligands to the substrate. We find that although the rupture forces for multiple carbohydrate connections to a single protein are larger than the rupture force for a single connection, they do not scale additively with increasing number.

Force spectroscopy of the double-tethered concanavalin-A mannose bond.

We present the measurement of the force required to rupture a single protein-sugar bond using a methodology that provides selective discrimination between specific and nonspecific binding events and helps verify the presence of a single functional molecule on the atomic force microscopy tip. In particular, the interaction force between a polymer-tethered concanavalin-A protein (ConA) and a similarly tethered mannose carbohydrate was measured as 47 +/- 9 pN at a bond loading rate of approximately 10 nN/s. Computer simulations of the polymer molecular configurations were used to determine the angles that the polymers could sweep out during binding and, in conjunction with mass spectrometry, used to separate the angular effects from the effects due to a distribution of tether lengths.