Cetek Corporation

Northeastern University

Yuriy M Dunayevskiy

Dallas E Hughes

James L Waters

Barry L Karger

Paul M Zavracky

Frantisek Foret

Andrew S Weiskopf

E Nicol McGruer

Qifeng Xue

The invention encompasses an improved, rapid, size-exclusive method for screening for small molecular weight ligands that bind specifically to a protein target, using size-exclusion separation, ultrafiltration, and mass spectrometry.

Size-exclusion-based extraction of affinity ligands and active compounds from natural samples

The invention relates to a capillary electrophoresis-based method of screening complex materials for any unidentified affinity ligand that binds to a target of interest. The method subjects a plug of a mixture of the target and a complex material sample, and a separate plug of a known, tight-binding competitive ligand, to capillary electrophoresis under conditions optimized to allow mingling of the two plugs during the capillary electrophoresis run. Preferably, migration of the competitive ligand is tracked.

Capillary electrophoresis method for screening for affinity ligands using a detectable competitive ligand

The invention relates to capillary electrophoretic methods for detecting ligands or hit compounds that can bind to a selected target at or above a selected binding strength. The method allows one to rank various ligands based on their relative affinity, i.e., the relative stability of the target/ligand complex during capillary electrophoresis under selected conditions. The method also enables selective detection of strong-to-moderate binding hit compounds, even in the presence of high concentrations of weaker, competitive hit compounds.

Capillary electrophoretic method to detect target-binding ligands and to determine their relative affinities

This invention combines a capillary electrophoresis (CE) technique for screening complex biological samples with mass spectrometry (MS), to provide a streamlined procedure for identifying and characterizing candidate ligands in a complex biological sample that bind at a selected binding strength to a selected target molecule. The method of the invention advantageously identifies and characterizes tight-binding ligands when high concentrations of weak ligands are present in the sample, which may mask lower concentrations of tight-binding ligands in the sample. The method involves interfacing a capillary from a CE instrument with a post-capillary mass spectrometer to provide direct mass analysis of target/ligand complexes that migrate stably through the CE instrument. All weaker-binding ligands will not be detected during the MS analysis because they dissociate from the target early during the CE run, before reaching and entering the mass spectrometer. Therefore, this method can identify and structurally characterize moderate-to-tight-binding ligands in complex biological samples, even in the presence of high concentrations of weak-binding ligands.

Method to detect and analyze tight-binding ligands in complex biological samples using capillary electrophoresis and mass spectrometry

This invention relates to a competitive-binding, capillary electrophoretic method of detecting new therapeutic regulatory (modulating) and diagnostic compounds in natural samples and other complex biological materials. The present method generally comprises mixing a preselected, detectable target with a sample of complex biological material to produce a first, sample/target mixture capillary electrophoresis apparatus. Subsequently, the first mixture is mixed with a pre-selected, tight-binding competitive ligand (TBCL), prior to produce a second, sample/target/TBCL mixture, for a predetermined optional incubation period sufficient to allow the TBCL to bind a pre-selected percentage of the available target in the absence of any other ligand. An aliquot of the second mixture is subsequently subjected to pre-optimized capillary electrophoresis, during which the migration of the target is monitored. The presence of a potential new compound is indicated by the increase in the peak area of the unbound target peak and/or decrease in the peak area of the TBCL/target complex peak. A capillary electrophoretic profile of the second mixture is produced, which may be compared to a reference standard. The reference standard typically comprises a capillary electrophoretic profile or migration pattern of the target when mixed with a TBCL in an absence of any other competing ligand under similar, pre-selected capillary electrophoretic conditions.

Capillary electrophoretic methods to detect new biologically active compounds in complex biological material

A microscale fluid handling system that permits the efficient transfer of nanoliter to picoliter quantities of a fluid sample from the spatially concentrated environment of a microfabricated chip to 'off-chip' analytical or collection devices for further off-chip sample manipulation and analysis is disclosed. The fluid handling system is fabricated in the form of one or more channels, in any suitable format, provided in a microchip body or substrate of silica, polymer or other suitable non-conductive material, or of stainless steel, noble metal, silicon or other suitable conductive or semi-conductive material. The microchip fluid handling system includes one or more exit ports integral with the end of one or more of the channels for consecutive or simultaneous off-chip analysis or collection of the sample. The exit port or ports may be configured, for example, as an electrospray interface for transfer of a fluid sample to a mass spectrometer.

Growing community of inventors

Natick, MA, United States of America

Yuriy M Dunayevskiy