Genetic incorporation of multiple unnatural amino acids into proteins in mammalian cells.

enables the expression of proteins in mammalian cells incorporating one unnatural amino acid (UAA) into multiple sites, as well as two different UAAs into distinct sites in a protein of interest. The utility of this technology was demonstrated by generating a full-length antibody, site-specifically conjugated to a drug and a fluorophore, and characterizing its activity in vitro (see picture). Picture was cropped to fit the available space.

Synthesis of site-specific antibody-drug conjugates using unnatural amino acids.

Antibody-drug conjugates (ADCs) allow selective targeting of cytotoxic drugs to cancer cells presenting tumor-associated surface markers, thereby minimizing systemic toxicity. Traditionally, the drug is conjugated nonselectively to cysteine or lysine residues in the antibody. However, these strategies often lead to heterogeneous products, which make optimization of the biological, physical, and pharmacological properties of an ADC challenging.

Catalyst Chelation Effects in Organocatalyzed Ring-Opening Polymerization of Lactide.

(-)-Sparteine is a proven organocatalyst for the ring-opening polymerization (ROP) of l-lactide, which affords polymers of controlled molecular weight and narrow polydispersity. The recent worldwide shortage of (-)-sparteine has necessitated the identification of simple and cost-effective replacement ROP catalysts. A series of commercially available molecules was first identified through molecular modeling and then subsequently investigated for polymerizing l-lactide.

Chemistry and behavioral studies identify chiral cyclopropanes as selective α4β2-nicotinic acetylcholine receptor partial agonists exhibiting an antidepressant profile.

Despite their discovery in the early 20th century and intensive study over the last 20 years, nicotinic acetylcholine receptors (nAChRs) are still far from being well understood. Only a few chemical entities targeting nAChRs are currently undergoing clinical trials, and even fewer have reached the marketplace. In our efforts to discover novel and truly selective nAChR ligands, we designed and synthesized a series of chiral cyclopropane-containing α4β2-specific ligands that display low nanomolar binding affinities and excellent subtype selectivity while acting as partial agonists at α4β2-nAChRs.

Targeting cell surface alpha(v)beta(3) integrin increases therapeutic efficacies of a legumain protease-activated auristatin prodrug.

Novel monomethylauristatin E (MMAE) prodrug 8 was designed and prepared that bound cell surface glycoprotein integrin αvβ3, and was activated using legumain protease as a catalyst. Upon activation, prodrug 8 strongly induced the death of MDA-MB-435 cells that express integrin αvβ3 on cell surface. Efficacies of prodrug 8 were also determined in vivo using animal models of 4T1 murine breast cancer, D121 Lewis lung carcinoma, and MDA-MB-435 human breast cancer.

Chemically programmed antibodies targeting multiple alpha(v) integrins and their effects on tumor-related functions in vitro.

Integrins αvβ3 and αvβ6 are highly expressed on tumor cells and/or by the tumor vasculature of many human cancers, and represent promising targets for anticancer therapy. Novel chemically programmed antibodies (cpAbs) targeting these integrins were prepared using the catalytic aldolase Antibody (Ab) programming strategy. The effects of the cpAbs on cellular functions related to tumor progression were examined in vitro using tumor cell lines and their cognate integrin ligands, fibronectin and osteopontin.

Chemistry and pharmacology of nicotinic ligands based on 6-[5-(azetidin-2-ylmethoxy)pyridin-3-yl]hex-5-yn-1-ol (AMOP-H-OH) for possible use in depression.

AMOP-H-OH (sazetidine-A; 6-[5-(azetidin-2-ylmethoxy)pyridin-3-yl]hex-5-yn-1-ol) and some sulfur-bearing analogues were tested for their activities in vitro against human alpha4beta2-, alpha4beta4-, alpha3beta4*- and alpha1*-nicotinic acetylcholine receptors (nAChRs). AMOP-H-OH was also assessed in an antidepressant efficacy model. AMOP-H-OH and some of its analogues have high potency and selectivity for alpha4beta2-nAChRs over other nAChR subtypes.