Dana-farber-cancer Institute Inc.

Peter D Senter

Walter A Blattler

John M Lambert

Immunotoxins having improved toxic activity have the composition ##STR1## wherein Toxin-NH is a ribosome-inactivating protein containing no accessible sulfhydryl groups, n is an integer from 1 to 5, m is an integer from 1 to 5, and NH-Antibody is a monoclonal antibody specific to eucaryotic cells or antigens associated therewith. The immunotoxins are made by reacting the Toxin-NH with an iminothiolester salt to form a first conjugate, reacting the NH-Antibody with N-succinimidyl-3-(2-pyridyldithio) propionate to form a second conjugate, and reacting the two conjugates to form the immunotoxin.

Gelonin immunotoxin

A photo-cleavable compound for delivery and release of a biologically active substance to selected target cells; the compound includes a binding partner for a specific cell-surface receptor of those target cells, the biologically active substance to be delivered, and a photo-cleavable bridge between the binding partner and the biologically active substance. When the compound is exposed to a heterogeneous population of target and non-target cells, it binds selectively to the receptors on the surface of the target cells. Exposing the compound to light of selected wave length cleaves it, yielding the active substance.

Cell-delivery agent

Amino-sulfhydryl cross-linking reagents that are cleavable under mildly acidic conditions are disclosed. Also disclosed are methods of making the cross-linkers, as well as methods of using the cross-linkers, e.g., to deliver a biologically active substance across the membranes of selected cells in a heterogeneous cell population; once inside the cell the active substance is released, intact, by the transient, mild acidity of certain cell structure. Finally, a method of characterizing complex multi-chain protein structures is disclosed.

Acid-cleavable compound

Amino-sulfhydryl cross-linking reagents that are cleavable under mildly acidic conditions are disclosed. Also disclosed are methods of making the cross-linkers, as well as methods of using the cross-linkers, e.g., to deliver a biologically active substance across the membranes of selected cells in a heterogeneous cell population; once inside the cell the active substance is released, intact, by the transient, mild acidity of certain cell structures. Finally, a method of characterizing complex multi-chain protein structures is disclosed.

Growing community of inventors

Jamaica Plain, MA, United States of America

Peter D Senter