Charge isomers

Hedrick, JL Smith, AJ, Size and Charge Isomer Separation and Estimation of Molecular Weights of Proteins by Disc Gel Electrophoresis, Archives of Biochemistry and Biophysics 126, 155, 1968. 

The first example in Figure 11.1 shows a pyrimidine trione compound bound to the active site of stromelysin. In order to get the interaction of one of the acidic pyrimidine nitrogens with the zinc cation correctly, the deprotonated negatively charged isomer has to be considered. 

Conversion, mole % of charge Isomer yield, mole % of charge... 

A number of workers have purified the hepatic alpha-class GST and shown that they are represented by multiple isoenzymes. Kamisaka et al. (Kl) originally observed five basic forms of GST (a-e), which had different p/ values but were indistinguishable by other criteria. It was, therefore, proposed that these enzymes are charge isomers formed as a result of deamination in vivo of a single gene product. Subsequent studies have shown, however, that the basic forms of GST present in human liver constitute two immunochemically and catalytically distinct... 

Hedrick, J.L., Smith, A.J., 1968. Size and charge isomer separation and estimation of molecular weights of proteins by disc gel electrophoresis. Arch. Biochem. Biophys., 126 155-164. 

Table 2. Physicochemical data of Cu Zn superoxide dismutases obtained by different isolation techniques. Aqueously isolated charge isomers I and II are compared with the enzymes which were isolated from haemolysate previously treated with chloroform/ethanol or heating to 75 °C for IS minutes...

Essentially no profound changes are seen. Isolated superoxide dismutase employing chloroform/ethanol treatment had a slightly different electrophoretic pattern compared to the aqueously isolated enzyme. The quantity of charge isomer II was diminished to a minor extent. 

Both charge isomers have a relative molecular mass of32,000 daltons. The isomerism is attributed to the different isoelectric points of the proteins No differences were found in metal content, antigenicity, electron paramagnetic resonance and electron absorption spectroscopy Holo- and apo-superoxide dismutase, which have electro-... 

Previously, the charge isomers of aqueously isolated bovine erythrocyte superoxide dismutase were separated and subjected to many biophysical investigations including the comparison with the enzymes isolated by the Tsushihashi-procedure Amino... 

Fig. 6. Circular dichroism of the charge-isomers from aqueously isolated CujZnjSuperoxide dismu-tase. The molecular ellipticity at 261 nm of charge isomer 1 is twice as high compared to that of charge isomer II. Trenting charge isomer 1 with H Oj the band at 261 nm is levelled off and a new Cotton band is seen at 295 nm...

There are other CPA inhibitors reported from a parasitic roundworm Ascaris lumbricoidesy They have a molecular weight of 7.5 kDa. with about 65 residues that seem to be charge isomers. The apparent Ki values for... 

These simple rules allow very rapid encoding of most chemical structures and need only a few simple additions to cope with other atoms, charges, isomers, etc. Specification of atoms not in the organic subset, for example, is coded by use of an atomic symbol within square brackets. An extensive description of the SMILES system is given by Weininger and Weininger (1990). 

Conditions affecting the in vitro synthesis of poly-D-galacturonase by Fusarium oxysporum have been studied, and the enzyme has been isolated by ion-exchange chromatography. The preparation contained two distinct isoenzymes that behaved as charge isomers on polyacrylamide gel electrophoresis. Some properties of the isoenzymes (mol. wt. 3.7 x 10 ), which contain covalently linked carbohydrate residues, were compared. 

Vollet J, Stosser G, Schnijckel H (2007) New structures of low valent A1 hypersilanides a negatively charged isomer with a ctos-o-A Si-structure potentially indicates a new entry in polyhedral AlmSvframeworks. Inorg Chim Acta 360 1298... 

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