Mechanistic similarity and diversity among the guanidine-modifying members of the pentein superfamily

Abstract

The pentein superfamily is a mechanistically diverse superfamily encompassing both noncatalytic proteins and enzymes that catalyze hydrolase, dihydrolase and amidinotransfer reactions on guanidine substrates. Despite generally low sequence identity, they possess a conserved structural fold and display common mechanistic themes in catalysis. The structurally characterized catalytic penteins possess a conserved core of residues that include a Cys, His and two polar, guanidine-binding residues. All known catalytic penteins use the core Cys to attack the substrate’s guanidine moiety to form a covalent thiouronium adduct and all cleave one or more of the guanidine C–N bonds. The mechanistic information compiled to date supports the hypothesis that this superfamily may have evolved divergently from a catalytically promiscuous ancestor.

Design, synthesis, and in vitro evaluation of an activity-based protein profiling (ABPP) probe targeting agmatine deiminases

“…The organics were dried over sodium sulfate, and concentrated under reduced pressure to yield the title compound as a colorless oil (2.06 g, 8.82 mmol, 71%). 1 168.43, 133.82, 131.98, 123.09, 62.42, 37.76, 32.07, 28.26, 22.94.…”

“…The organics were washed with brine (60 mL), dried over anhydrous sodium sulfate, and concentrated under reduced pressure to yield the title compound as an off-white foam (1.41 g, 2.7 mmol, 88%). 1 …”

“…The residue was purified on silica gel (30% ethyl acetate/hexane) to yield the product as a clear colorless oil (0.54 g, 1.82 mmol, 80%). 1 Potassium carbonate (0.50 g, 3.6 mmol) was added to a solution of N-[(4-triphenylmethylamino)butyl]-4-nitrobenzenesulfonamide (0.93 g, 1.8 mmol) and N-(5-bromopentyl)phthalimide (0.54 g, 1.8 mmol) in DMF (12 mL). The mixture was stirred at 95°C and monitored by TLC (5% EtOAc in DCM).…”

“…1 H and 13 C NMR spectra were collected on a Varian 500 MHz spectrometer. Chemical shifts are reported in d (ppm) units relative to the solvent peak.…”

“…Examples of these enzymes, known as guanidinium group modifying enzymes (GMEs), include amidino transferases (ATs), dimethylargininedimethylaminohydrolases (DDAHs), L-arginine deiminases (ADIs), protein arginine deiminases (PADs), and dihydrolases. 1 GMEs modify the guanidinium group of their respective substrates by either hydrolytic or transferase activities. One feature that is common to the GMEs is a conserved cysteine residue within the active site.…”