The eye lens crystallins represent an ideal target for studying the effects of aging on protein structure. Herein we examine separately the water-soluble (WS) and water-insoluble (WI) crystallin fractions and identify sites of isomerization and epimerization. Both collision-induced dissociation and radical-directed dissociation are needed for detection of these non-mass-shifting post-translatio...

Femtosecond time-resolved absorption measurements were performed to investigate the influence of the pH, imidazole concentration, and point mutations on the isomerization process of Channelrhodopsin-2. Apart from the typical spectral characteristics of retinal isomerization, an additional absorption feature rises for the wild-type (wt) on a timescale from tens of ps to 1 ns within the spectral ...

The degradation of proteins by asparagine deamidation and aspartate isomerization is one of several chemical degradation pathways for recombinant antibodies. In this study, we have identified two solvent accessible degradation sites (light chain aspartate-56 and heavy chain aspartate-99/101) in the complementary-determining regions of a recombinant IgG1 antibody susceptible to isomerization und...

The planar isomerization routes of the vinylidene/acetylene cation in the lowest electronic states are accurately examined for the first time, by using large scale MRCI and CCSDT calculations in a complementary way. They are compared with the similar calculations performed for the neutral ground state isomerization. An accurate value of the adiabatic ionization potential of vinylidene (11.26 eV...

Unusual N-acetylated sugars have been observed on the O-antigens of some Gram-negative bacteria and on the S-layers of both Gram-positive and Gram-negative bacteria. One such sugar is 3-acetamido-3,6-dideoxy-α-d-galactose or Fuc3NAc. The pathway for its production requires five enzymes with the first step involving the attachment of dTMP to glucose-1-phosphate. Here, we report a structural and ...

Isomerization-linear-hydroformylation is demanding, however, not an addressed issue, for the production of value-added linear aldehydes by converting cheap and abundant internal alkenes available from bio- & petrochemical industry. In this paper, a dual metal catalysis system combining Ru-isomerization catalyst Rh-linear-hydroformylation satisfying “4S” criterions was reported isomerization-lin...

The first Ni-catalysed alkene isomerization of allylamides for the synthesis of enamides was demonstrated. Various substituted N-allylamides were found to be suitable substrates for this isomerization. Isotopic labelling experiments showed that it is an intramolecular hydrogen transfer process.

The effect of H2 on isomerization pathways and on the acid site density on WOx-ZrO2 catalysts was explored using kinetic measurements of acid-catalyzed o-xylene isomerization reactions. Initial o-xylene isomerization rates on WOx-ZrO2 at 523 K are proportional to the H2 concentration even though H atoms are not involved directly in reaction turnovers, as shown by the low deuterium content in th...