BACKGROUND Antibodies are prototypes of multimeric proteins and consist of structurally similar domains. The two variable domains of an antibody (VH and VL) interact through a large hydrophobic interface and can be expressed as covalently linked single-chain Fv (scFv) fragments. The in vitro folding of scFv fragments after long-term denaturation in guanidinium chloride is known to be slow. In o...

A straightforward heteronuclear pseudo-3D NOESY-HSQC pulse sequence using radiation damping to selectively invert magnetization at the water frequency was developed to estimate the amide proton exchange rates in 15N-labelled proteins. The peak intensities in the resultant 2D spectrum allow a direct classification of amide proton exchange rates according to short (ms), intermediate (ms to s) or ...

An anisotropic model for the fabrication of annealed and reverse proton exchange waveguides in lithium niobate is presented. We characterized the anisotropic diffusion properties of proton exchange, annealing and reverse proton exchange in Z-cut and X-cut substrates using planar waveguides. Using this model we fabricated high quality channel waveguides with propagation losses as low as 0.086 dB...

η meson production in both proton-proton and proton-neutron collisions is investigated within a relativistic meson exchange model of hadronic interactions. It is found that the available cross section data can be described equally well by either the vector or pseudoscalar meson exchange mechanism for exciting the S 11 (1535) resonance. It is shown that the analyzing power data can potentially b...

Proton exchange membrane fuel cells are promising energy sources that produce electrical currents with almost null pollutant emissions, and they have been received growing attention in recent years. Maintaining a fuel cell system in correct operating conditions requires good system control. Based on the mathematical model of proton exchange membrane fuel cells, model linearization is carried ou...

Human oxyhemoglobin showed a biphasic autoxidation curve containing two rate constants, i.e. kf for the fast autoxidation due to the alpha chains, and ks for the slow autoxidation of the beta chains, respectively. Consequently, the autoxidation of the HbO2 tetramer produces two different curves from the pH dependence of kf and ks. The analysis of these curves revealed that the beta chain of the...

Kornblum and Delamare showed the first decomposition of dialkyl peroxides by base-catalyzed rearrangement. They reported that 1-[1-(tert -butylperoxy)ethyl] benzene 1 gives acetophenone and tert-butanol by treatment with bases such as KOH, NaOEt, and piperidine. Milas and Surgenor reported previously the stability of 2-(tert -butylperoxy)-2-methylpropane against strong bases. Kornblum and Delam...

This communication describes a chiral base-catalyzed asymmetric [1,3]-proton shift of trifluoromethyl ketimines, giving a wide variety of trifluoromethyl aldimines containing various functional groups with up to 94% ee.

A pair of bpe-H(+) ligands in a zwitter-ionic complex undergoes photochemical cycloaddition quantitatively accompanied by proton transfer and the cyclobutane ring isomerizes slowly in solution to two more isomers, catalyzed by CF(3)CO(2)H acid.