Biochemical modification

The subtle interaction of air pollutants with these other stressors to plants and vegetation is the subject of ongoing research. For some plant systems, exposure to air pollutants may induce biochemical modifications which interfere with the water balance in plants, thereby reducing their ability to tolerate drought conditions. 

Biochemical modifications of receptors / Modulation of second messaging systems and gene expression / Changes in extracellular ion concentrations... 

HMGA biochemical modifications a labile regulatory code... 

Over the last several years a substantial body of evidence has accumulated indicating the types and patterns of secondary biochemical modifications present on histones [42,43], transcriptional co-activators [44] and the HMGA proteins [33]... 

Recent advances in mass spectrometry (MS) technology have provided researchers with an unparalleled ability to identify the types and patterns of secondary biochemical modifications found on proteins in living cells. Matrix-assisted laser desorption/ionization-MS (MALDI-MS) analyses have shown, for example, that HMGA proteins in vivo are simultaneously subject to complex patterns of phosphorylation, acetylation and methylation and that, within the same cell type, different isoforms of these proteins can exhibit quite different modification patterns [33]. Furthermore, these in vivo modifications have been demonstrated to markedly alter the binding affinity of HMGA proteins for both DNA and chromatin substrates in vitro [33]. Nevertheless, due to their number and complexity, it has been difficult to determine the actual biological function(s) played by these biochemical modifications in living cells. 

An intriguing feature of nicotinic acid formation in animals is that it is a metabolite produced from the amino acid tryptophan. This means the pyridine ring is actually formed by biochemical modification of the indole fused-ring system (see Section 11.8.2), and, as you might imagine, it involves a substantial sequence of transformations. 

Surprisingly, little attention has been paid to (i) the mechanism of phenylpropanoid transport from the cytoplasm into the cell wall and (ii) subsequent chemical and biochemical modifications within the cell wall... 

Since the protein scaffold is commonly not very stable, many methods have been used for stabilization presence of additives, immobilization by multiple-point attachment, stabilization by chemical or biochemical modification and by protein engineering, and several others. 

Residues of antimicrobial agents tend to be present at their highest levels in the liver and kidney, as well as the site of injection (if that is the route of application). The liver is the main site of biochemical modification of antimicrobial substances, as the body tries to convert them to less toxic... 

G. Paganelli. 1998. Biochemical modifications of avidin improve pharmacokinetics and biodistribution, and reduce immuno-genicity. Br. J. Cancer 78 189-197. 

Rosebrough S.F., and D.F. Hartley. 1996. Biochemical modification of streptavidin and avidin in vitro and in vivo analysis. 

A monoclonal antibody which reacts with an epitope within the M domain has recently been used to check whether it influences the receptor s DNA binding properties [65]. The immune complex with wild-type receptors was indeed found to chromatograph on DNA-cellulose similar to nt1 mutant receptors or the chymo-trypsin-degraded wild-type. Reaction with the antibody mimics the removal of the M domain which suggests that biochemical modifications of the M domain could... 

Figure 6.11 Structure and sites of biochemical modification of phytoecdysteroids. The structures of the most commonly reported phytoecdysteroid, 20-hydroxyecdysone, and a 24-alkylphytoecdysteroid, cyasterone. Some common sites of biochemical modifications reported for phytoecdysteroids. (From Adler and Grebenok, 1999.)...

Koncki, R. Hulanicki, A. Glab, S., Biochemical modifications of membrane ion-selective sensors, Trends Anal. Chem. 1997, 16, 528-536... 

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