Label-free detection of the interaction between hexahistidine-tagged human κ-opioid receptor membrane protein and anti-His antibody is demonstrated in liquid by an optical microelectromechanical system utilizing electromagnetically actuated microresonators. Shift in resonance frequency due to accretion of mass on the sensitive surface of microresonators is monitored via an integrated optical re...

We evaluate the ability of hexahistidine (His6) tags on peptide and protein substrates to recruit deoxyribozymes for modifying those substrates. For two different deoxyribozymes, one that creates tyrosine-RNA nucleopeptides and another that phosphorylates tyrosine side chains, we find substantial improvements in yield, kobs, and Km for peptide substrates due to recruiting by His6/Cu(2+). Howeve...

We present a molecular theory to study the adsorption of different species within pH-sensitive hydrogel nanofilms. The theoretical framework allows for a molecular-level description of all the components of the system, and it explicitly accounts for the acid-base equilibrium. We concentrate on the adsorption of hexahistidine, one of the most widely used tags in bio-related systems, particularly...

The polar flagellum of Vibrio alginolyticus is rotated by the sodium motor. The stator unit of the sodium motor consists of four different proteins: PomA, PomB, MotX and MotY. MotX and MotY, which are unique components of the sodium motor, form the T-ring structure attached to the LP ring in the periplasmic space. MotY has a putative peptidoglycan-binding motif in its C-terminal region and MotX...

The recombinant expression of soluble proteins in Escherichia coli continues to be a major bottleneck in structural genomics. The establishment of reliable protocols for the performance of small-scale expression and solubility testing is an essential component of structural genomic pipelines. The SSGCID Protein Production Group at the University of Washington (UW-PPG) has developed a high-throu...

BACKGROUND Functional Genomics, the systematic characterisation of the functions of an organism's genes, includes the study of the gene products, the proteins. Such studies require methods to express and purify these proteins in a parallel, time and cost effective manner. RESULTS We developed a method for parallel expression and purification of recombinant proteins with a hexahistidine tag (H...

A practically simple top-down process for the exfoliation of graphene (GN) and few-layer graphene (FLG) from graphite is described. We have discovered that a biocompatible amphiphilic pyrene-based hexahistidine peptide is able to exfoliate, functionalize, and dissolve few layer graphene flakes in pure water under exceptionally mild, sustainable and virtually innocuous low intensity cavitation c...

Many proteins that accumulate in the form of insoluble aggregates when they are overproduced in Escherichia coli can be rendered soluble by fusing them to E. coli maltose binding protein (MBP), and this will often enable them to fold in to their biologically active conformations. Yet, although it is an excellent solubility enhancer, MBP is not a particularly good affinity tag for protein purifi...

A surface plasmon resonance imaging-based Ni(2+)-iminodiacetic acid-coated gold chip system was developed to enable specific detection of a hexahistidine-tagged recombinant protein in crude extracts or in column chromatography fractions. This system is especially advantageous for high-throughput analysis of multiple proteins.

Fluorescent probes are essential for the exploration of protein function, detection of molecular interactions, and conformational changes. The nitrilotriacetic acid derivatives of different chromophores were successfully used for site-selective noncovalent fluorescence labeling of histidine-tagged proteins. All of them, however, suffer from the same drawback--loss of the fluorescence upon bindi...