Ia, Inc.

University of Louisville Research Foundation

John R Erb-Downward

James G Downward, Iv

Judith Louise Erb

James L Wittliff

James L Witliff

Otho Ulrich

There is provided an apparatus for screening pharmacological agents for agents which induce regression of cancer. The apparatus includes an evanescent sensing device, at least one sensor having affixed to its surface molecules of a first type, which have affinity for molecules of a biological receptor, the surface molecule and receptor molecule combination having the effect that, in vivo, the binding affects the rate of transcription of gene products, and a molecular tag wherein the molecular tag is bound to the sensor wherein the binding between molecules of the first type and molecules the biological receptor cause the tag to produce a alteration in signal recorded by the evanescent sensing device, the tag also being bound to molecules of a second type, the molecules of the second type having affinity for the receptor molecules. Also provided is a method for screening pharmacological agents to determine agents which induce regression of cancer by contacting extract from a tumor tissue biopsy with a molecular tag, thereby causing the tag to bind to receptor molecules present in the tumor tissue biopsy, flowing the tag sample extract through a sensor, as set forth above, and recording the time course of signal observed by the evanescent sensing device, introducing pharmacological agents to be accessed to the tag sample extract, flowing the tag sample extract through the sensor again and recoding the time course of signal observed by the evanescent sensing device, and using the data to evaluate the impact of the pharmacological agents on the rate of transcription of gene products.

Method and apparatus for measurement of the effect of test compounds on signal transduction at the level of biological receptors

A method and apparatus for measuring binding between a plurality of molecules of a biological receptor protein and a plurality of molecules of a type which binds to said biological receptor is presented. Apparatus utilizes a sensor possessing a waveguide to which have been attached in close proximity to its surface, features resembling molecules having binding affinity for said biological receptor. Light is injected into said waveguide so as to produce an evanescent field at its surface. Molecules of receptor protein are tagged with a tag belonging to that class of chemicals which alters a characteristic of light, when said light passes through said chemical tag. Apparatus utilizes a rapid means of monitoring the change in optical signal coming from the waveguide as binding proceeds between tagged receptor protein and the binding molecular feature of the waveguide. This allows direct measurement of binding and dissociation rates between the receptor and the binding feature of the waveguide. By using a waveguide having a feature resembling a ligand for the receptor, the potential hormonal activity of a test substance may be evaluated from its ability to compete with the waveguide for binding with the receptor. The effect of a test compound on binding of receptor protein to a subsequent element in a hormonal signal transduction mechanism is evaluated by measuring the impact of the test compound on binding between receptor protein and a feature resembling said next element of the signal transduction mechanism. Methods are provided whereby such data may be used to compute affinity constants, binding activity, complex affinity constants resulting from cooperativity, and kinetic parameters for the receptor and test ligand and for the receptor and the next element of the signal transduction mechanism. Preferred embodiments of the invention illustrate application of the method and apparatus to measuring binding between biological receptors and their nuclear response elements, and the use of this type of measurement for assessment of the activity of estrogen mimics present in a test sample, and for evaluation of pharmaceuticals intended to treat hormone dependent cancers.

A method and apparatus for measuring binding between a plurality of molecules of a first type and a plurality of molecules of a second type is presented. Apparatus utilizes a sensor possessing a waveguide to which have been attached in close proximity to its surface, features resembling molecules of said first type. Light is injected into said waveguide so as to produce an evanescent field at its surface. Molecules of said second type are tagged with a tag belonging to that class of chemicals which alters a characteristic of light, when said light passes through said chemical tag. Apparatus utilizes a rapid means of monitoring the change in optical signal coming from said waveguide as binding proceeds between tagged molecules of type 2 and the feature resembling molecules of type 1 on said waveguide. This allows direct measurement of binding and dissociation rates between the two types of molecules. Methods are provided whereby such data may be used to compute affinity constants, binding activity, complex affinity constants resulting from cooperativity, and kinetic parameters for the molecular pair. Preferred embodiments of the invention illustrate application of the method and apparatus to measuring binding between biological receptors and their nuclear response elements, and the use of this type of measurement for assessment of the activity of hormonal mimics present in a sample, for evaluation of pharmaceuticals intended to treat hormone dependent cancers, and for evaluation of tissue biopsy samples to detect mutant forms of the p53 protein.

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Ann Arbor, MI, United States of America

John R Erb-Downward