Methods and compositions for modulating BCL-2 family polypeptides
Inventors
Walensky, Loren D. • Tjandra, Nico • Gavathiotis, Evripidis • Suzuki, Motoshi • Bird, Gregory
Assignees
Dana Farber Cancer Institute Inc • US Department of Health and Human Services
Publication Number
US-8921323-B2
Publication Date
2014-12-30
Expiration Date
2028-09-26
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Abstract
The present invention is based, at least in part, on the identification of a novel active site on BCL-2 family polypeptide such as BAX, which when bound by a compound, modifies the activity of the BCL-2 family polypeptide.
Core Innovation
The invention is directed to methods, kits, and compositions for modulating the activity of BCL-2 family polypeptides, such as BAX, by targeting a novel regulatory active site on these proteins. The compounds and methods modulate apoptotic or other disease-related activities of BCL-2 family polypeptides by binding to an active site formed primarily by the juxtaposition of alpha helices 1 and 6 on BAX. The active site contains a hydrophobic patch and a perimeter of charged and hydrophilic residues, including specific amino acid residues such as Glu17, Met20, Lys21, Thr22, and others identified in SEQ ID NO:1. Binding of a compound to this active site modifies BAX’s apoptotic activity, either activating or inhibiting it.
The background problem addressed is the regulation of apoptosis by BCL-2 family proteins, which is critical for organism homeostasis, development, and disease states. While anti-apoptotic proteins such as BCL-2 protect against cell death, pro-apoptotic multidomain proteins like BAX are gateways to apoptosis. Prior hypotheses regarding BAX activation by BH3-only proteins have been uncertain due to lack of direct binding data and structural evidence. Thus, there existed a need for methods and compounds that could directly modulate BAX and other BCL-2 family members by targeting a specific, novel active site to therapeutically regulate apoptosis.
The disclosure enables identification and characterization of this novel active site and provides assays to identify compounds, including BH3 polypeptides and their mimetics, that bind to this region and modulate BCL-2 family polypeptide activity. The methods include using three-dimensional structural templates for screening candidate compounds. Further, stapled BH3 peptides (SAHBs), including BIM, BID, PUMA, and BAX BH3 SAHBs, have been shown to bind this site with high specificity and activate BAX, triggering conformational changes, oligomerization, and apoptotic functions. The invention also provides crosslinkable polypeptides and methods to study and identify homologous active sites in other BCL-2 family members or proteins.
Claims Coverage
The patent contains one independent claim directed to a method of treating leukemia or lymphoma using a specific cross-linked BIM BH3 polypeptide and a BAX polypeptide with defined cross-links.
Method of treating leukemia or lymphoma using a cross-linked BIM BH3 polypeptide and cross-linked BAX polypeptide
A method comprising administering to a subject an effective amount of a BIM BH3 polypeptide consisting of at least 20 contiguous amino acids of SEQ ID NO: 3, where the side-chains of Arg at position 10 and Glu at position 14 have been replaced by a cross-link, and a BAX polypeptide consisting of SEQ ID NO: 14, where the side-chains of Gly at position 11 and Ala at position 15 have been replaced by a cross-link, such that the subject is treated for leukemia or lymphoma.
The independent claim covers a therapeutic method employing specifically cross-linked BIM BH3 and BAX polypeptides to treat leukemia or lymphoma, emphasizing the use of polypeptides with defined stapled cross-links for modulating BAX activity in treatment.
Stated Advantages
The invention provides specific and high potency functional activation of BAX by stapled BH3 peptides leading to apoptosis induction.
Crosslinked stapled BH3 polypeptides exhibit improved stability, enhanced alpha-helicity, and greater resistance to proteolytic cleavage and heat.
The methods and compounds enable targeted modulation of BCL-2 family members to treat or prevent disorders characterized by deregulated apoptosis, including cancers and diseases related to excessive cell death or survival.
Documented Applications
Treatment and/or prevention of disorders characterized by deregulation of BCL-2 family members, including cancer (solid tumors, leukemias, lymphomas), autoimmune disease, diabetes, neurodegenerative disease, heart attack, and stroke.
Treatment of hyperproliferative disorders such as chemoresistant cancer, including cancers resistant to ABT-737 or ABT-263.
Use in in vitro and in vivo assays to identify modulators of apoptosis for therapeutic development.
Use in methods for identifying compounds which modulate BCL-2 family polypeptides by binding to a novel active site.
Interested in licensing this patent?