A novel surface-enhanced Raman scattering (SERS) method is demonstrated to detect L-histidine based on DNAzyme which can specifically recognize L-histidine. Through a target recycling cascade amplification strategy, the DNAzyme-based SERS sensing system affords very high sensitivity for L-histidine with a detection limit of 0.56 nM.

Common signal transduction mechanisms, generally referred to as histidine-to-aspartate (His-to-Asp) phosphorelays (or two-component regulatory systems), are involyed in a wide variety of cellular responses to environmental stimuli.i} Such a His-toAsp phosphorelay system generally consists of two or more common signal transducers; a sensor with histidine (His)-kinase activity, a histidine-contai...

L-Histidine and imidazole (the histidine side chain) significantly increase cAMP accumulation in intact LLC-PK1 cells. This effect is completely inhibited by isobutylmethylxanthine (IBMX). Histidine and imidazole stimulate cAMP phosphodiesterase activity in soluble and membrane fractions of LLC-PK1 cells suggesting that the IBMX-sensitive effect of these agents to stimulate cAMP formation is no...

Bacterial histidine kinases have been proposed as targets for the discovery of new antibiotics, yet few specific inhibitors of bacterial histidine kinases have been reported. We report here a novel thienopyridine (TEP) compound that inhibits bacterial histidine kinases competitively with respect to ATP but does not comparably inhibit mammalian serine/threonine kinases. Although it partitions in...

A histidine auxotroph of Saccharomyces cerevieiae has been used to metabolically incorporate [1,3-'"N%] histidine into yeast cytochrome c oxidase. Electron nuclear double resonance (ENDOR) spectroscopy of cytochrome a in the ['6N]h~stidine-substituted enzyme reveals an ENDOR signal which can be assigned to hyperfine coupling of a histidine "N with the low-spin heme, thereby unambiguously identi...

We have followed the in vitro degradation of rat histidine decarboxylase in a reconstituted system, containing only rat histidine decarboxylase (obtained by in vitro transcription and translation), calcium ions in the millimolar range of concentrations, and m-calpain. Under the experimental conditions used, m-calpain quickly and efficiently degraded rat histidine decarboxylase, giving rise to a...

A fluorescent hydroxyl- and hydrazone-based covalent organic framework (TFPB–DHTH COF) was synthesized as an “OFF–ON” sensor for cysteine l-histidine.

Molecular dynamics simulations of histidine-based dipeptides in water show that a protonated histidine side chain group has a propensity for forming like-charged contact pairs with another protonated histidine or with arginine. This effect is of similar strength to that in previously observed arginine-arginine pairing. Even stronger contact pairs are formed in singly protonated or deprotonated ...

1-Benzyl-2-(methylthio)-imidazole-5-ketone is obtained in a few simple steps starting from thiocyanate and glycine amide (glycin). Subsequent treatment with diethyl phosphorocyanidate and functional group manipulations gives 1-benzyl-5-chloromethyl-imidazolium chloride. This compound is converted under mild O'Donnell conditions into the corresponding L-histidine derivative. After deprotection L...

In bee venom phospholipase A2, histidine-34 probably functions as a Brønsted base to deprotonate the attacking water. Aspartate-64 and tyrosine-87 form a hydrogen bonding network with histidine-34. We have prepared mutants at these positions and studied their kinetic properties. The mutant in which histidine-34 is changed to glutamine is catalytically inactive, while the mutants in which aspart...