About Arbor Vita Corporation Science and Technology Importance to human biology PDZ proteins are named for the first letter of the first three proteins in the family to be discovered (PSD-95, DLG, and ZO-1). PDZs initiate and regulate the assembly of proteins including membrane proteins, cytoskeletal proteins, kinases, and other proteins. The effects of interrupting interactions of PDZ proteins with their protein ligand (PL) binding partners offer the potential for the development of treatments for cancer, inflammation, and neurological disorders among others. Ideal drug targets PDZ protein interactions are ideal small molecule targets in that each PDZ protein binds to its respective PL in a discrete, well-defined, and well-characterized binding pocket. The interaction is reminiscent of a “lock-and-key” enzyme pocket where small molecule therapeutics have been discovered to target kinases (viruses) and proteases (AIDS). Scientists at Arbor Vita Corporation have demonstrated that disrupting the PDZ/PL interaction can cause inactivation of critical signaling pathways within disease pathways forming the basis for developing therapeutics. Favorable side effect profile Many PDZ proteins and their respective PLs are expressed only in limited cell types. This allows development of specific therapeutics that target only those cells, thus reducing the risk of undesirable systemic side effects stemming from the inadvertent disruption of unrelated interactions. Proprietary tools to accelerate drug discovery Arbor Vita Corporation has developed the PDZ Drug Discovery PlatformTM, a specialized set of proprietary tools to accelerate the discovery of drugs targeting PDZ proteins: Reference set of all human PDZ proteins High through-put screen for PDZ interactions Predictive molecular modeling Laboratory information management system Diagnostic Spin-offs Arbor Vita Corporation is pursuing the development of diagnostic products capitalizing on the technology from our drug discovery programs. The company has projects for the detection of cervical cancer (HPV) and biological warfare agents such as anthrax.

Arbor Vita Corporation 772 Lucerne Drive Sunnyvale, CA 94085 Telephone (408) 585-3900 Fax (408) 585-3901 info@arborvita.com