Insight into the (enzyme-catalysed) modifications of homogalacturonan, the major structural domain of this polysaccharide which strongly influences the pectin structure function properties, can be obtained by in situ research tools.
To test whether pAp could also inhibit this heteromodification, we measured the poly(ADP-ribosyl)ation of histone H1 in the presence of various concentrations of pAp. Figure 4 shows a dose-dependent inhibition of the PARP-1-catalysed histone modification by pAp.
The light-sensitive modification (ruthenium catalysed) of the Belousov Zhabotinsky reaction exhibits various excitability regimes depending on the level of illumination.
Klungland and coworkers have provided evidence that mouse Alkbh8 and the catalysed mcmU wobble base modifications are vital for the translation of the reactive oxygen species detoxifying protein Gpx1 (Songe-Moller et al, 2010).
This modification, auto-catalysed by CUL3-RBX1, is aided by Nedd8-E3 ligases (Kurz et al, 2005; Rabut et al, 2011) and alters the flexibility of the C-terminal Cullin-RBX1 module to activate E3 ligase activity (Duda et al, 2008; Scott et al, 2014).
Retrograde trafficking of STx can be monitored using a recombinant STxBsulf cargo containing an accessible sulfation site that permits in vivo modification by the addition of SO42− in a reaction catalysed by TPST [ 22, 42].
There is ample evidence to support the notion that the most important mechanism of protein oxidative damage is metal-catalysed oxidation (MCO), resulting in cleavage of polypeptide backbone, cross linking, and modification of the amino acid side chains leading to the loss of protein function and to structural alteration [6].
Lipid A modifications are regulated by the environmental sensor-kinase transcriptional regulatory system PhoP-PhoQ and catalysed by PagP, PagL and LpxO which lead to acylation, deacylation and hydroxylation of the molecule, respectively [12], [13], [14].
Protein functionalities can be extended and modulated by enzyme-catalysed and spontaneous post-translational modifications (PTMs 1 such as phosphorylation, nitrosylation, acetylation, methylation, hydroxylation, glycosylation and the attachment of other small proteins.
