Production, characterization, and assessment of a stable analog of the response regulator CheY-phosphate from Thermotoga maritima

Phosphonopeptides containing free phosphonic groups: recent advances

Phosphonopeptides are mimetics of peptides in which phosphonic acid or related (phosphinic, phosphonous etc.) group replaces either carboxylic acid group present at C-terminus, is located in the peptidyl side chain, or phosphonamidate or phosphinic acid mimics peptide bond. Acting as inhibitors of key enzymes related to variable pathological states they display interesting and useful physiologic activities with potential applications in medicine and agriculture. Since the synthesis and biological properties of peptides containing C-terminal diaryl phosphonates and those with phosphonic fragment replacing peptide bond were comprehensively reviewed, this review concentrate on peptides holding free, unsubstituted phosphonic acid moiety. There are two groups of such mimetics: (i) peptides in which aminophosphonic acid is located at C-terminus of the peptide chain with most of them (including antibiotics isolated from bacteria and fungi) exhibiting antimicrobial activity; (ii) non-hydrolysable analogues of phosphonoamino acids, which are useful tools to study physiologic effects of phosphorylations.

Synthesis of a Stable Analog of the Phosphorylated Form of CheY: Phosphono-CheY

CheY is a response regulator of bacterial chemotaxis that is activated by phosphorylation of a conserved aspartate residue. However, studies of CheY-phosphate have proven challenging due to rapid hydrolysis of the aspartyl-phosphate in vitro. To combat this issue, we have designed a stable analog suitable for structural and functional studies. Herein, we describe a method for the chemical modification of Thermotoga maritima CheY to produce a phospho-analog designated as phosphono-CheY. Our modification produces a stable analog in the constitutively active form that enables the study of signal transfer to the downstream target.