Targeting Bacterial Cell Wall Peptidoglycan Synthesis by Inhibition of Glycosyltransferase Activity.

Synthesis of bacterial cell wall peptidoglycan requires glycosyltransferase enzymes that transfer the disaccharide-peptide from lipid II onto the growing glycan chain. The polymerization of the glycan chain precedes cross-linking by penicillin-binding proteins and is essential for growth for key bacterial pathogens. As such, bacterial cell wall glycosyltransferases are an attractive target for antibiotic drug discovery.

Measurement of glycolysis reactants by high-throughput solid phase extraction with tandem mass spectrometry: Characterization of pyrophosphate-dependent phosphofructokinase as a case study.

Glycolysis is a 10-step metabolic pathway involved in producing cellular energy. Many tumors exhibit accelerated glycolytic rates, and enzymes that participate in this pathway are focal points of cancer research. Here, a novel method for the measurement of glycolysis reactants from in vitro samples is presented.

Advances in label-free screening approaches for studying sirtuin-mediated deacetylation.

The sirtuin enzymes, a class of NAD(+)-dependent histone deacetylases, are a focal point of epigenetic research because of their roles in regulating gene expression and cellular differentiation by deacetylating histones and a host of transcription factors, including p53. Here, the authors present two label-free screening methodologies to study sirtuin activity using high-throughput mass spectrometry. The first method involves the detection of native peptides and provides a platform for more detailed mechanistic studies by enabling the concurrent and direct measurement of multiple modification states.

Advances in label-free screening approaches for studying histone acetyltransferases.

Histone acetyltransferases (HATs) catalyze the transfer of an acetyl group from an acetyl-coenzyme A donor molecule to specific lysine residues within proteins. The acetylation state of proteins, particularly histones, is known to modulate their intermolecular binding properties and control various cellular processes, most notably transcriptional activation. In addition, deregulation of HAT activity has been linked to the development of a number of cancers; therefore, compounds that affect these enzymes have strong potential as therapeutic agents.

A bifunctional platinum(II) antitumor agent that forms DNA adducts with affinity for the estrogen receptor.

A strategy is described for the re-design of DNA damaging platinum(II) complexes to afford elevated toxicity towards cancer cells expressing the estrogen receptor (ER). Two platinum-based toxicants are described in which a DNA damaging warhead, [Pt(en)Cl(2)] (en, ethylenediamine), is tethered to either of two functional groups. The first agent, [6-(2-amino-ethylamino)-hexyl]-carbamic acid 2-[6-(7alpha-estra-1,3,5,(10)-triene)-hexylamino]-ethyl ester platinum(II) dichloride ((Est-en)PtCl(2)), terminates in a ligand for the ER.

Mismatch repair proteins collaborate with methyltransferases in the repair of O(6)-methylguanine.

DNA repair is essential for combatting the adverse effects of damage to the genome. One example of base damage is O(6)-methylguanine (O(6)mG), which stably pairs with thymine during replication and thereby creates a promutagenic O(6)mG:T mismatch. This mismatch has also been linked with cellular toxicity.

A rationally designed genotoxin that selectively destroys estrogen receptor-positive breast cancer cells.

We describe a novel strategy to increase the selective toxicity of genotoxic compounds. The strategy involves the synthesis of bifunctional molecules capable of forming DNA adducts that have high affinity for specific proteins in target cells. It is proposed that the association of such proteins with damaged sites in DNA can compromise protein function and/or DNA repair resulting in increased toxicity.