Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Second virial coefficients and hence covolumes for self-interaction of five proteins, viz. ribonuclease, ovalbumin, bovine serum albumin, catalase and alpha-crystallin, have been determined by analyzing the concentration dependence of the partition coefficient obtained from frontal chromatographic studies on either Fractogel TSK HW55 or porous glass beads. The resulting estimates of the effective radii essentially duplicate their Stokes counterparts and thereby provide further justification for assuming the approximate identity of the thermodynamic and hydrodynamic radii of hydrated globular proteins. Gel chromatographic evaluation of second virial coefficients for protein/dextran systems has led to elimination of the sphere/sphere model as a valid thermodynamic description of the space-filling effects in protein/polymer mixtures, since it does not predict the observed independence of covolume, expressed per unit mass of polymer, upon size of the polymer. This requirement is met by the sphere/rod model [Edmond, E. & Ogston, A. G. (1968) Biochem. J. 109, 569-576] and also by the sphere/flexible-segment model [Hermans, J. (1982) J. Chem. Phys. 77, 2193-2203]. Furthermore, similar studies of the effect of solute radius on covolume for interaction with dextran T70 attest to the adequacy of either model for predicting the thermodynamic nonideality arising from the inclusion of dextrans in protein solutions, and also provide the relevant calibration of the model.
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PMID:Thermodynamic nonideality in macromolecular solutions. Evaluation of parameters for the prediction of covolume effects. 237 80

Affinity labelling with radioactive, periodate-oxidized tRNA has been used to investigate the structures of tRNA-binding sites in Escherichia coli aminoacyl-tRNA synthetases. Labelled peptides were isolated by means of a combination of techniques involving chymotryptic digestion of the enzyme, gel filtration, ribonuclease digestion of tRNA, chromatography on a TSK 2000 column and reversed-phase chromatography. An isocratic phenylthiohydantoin identification system has been interfaced to a sequencer, allowing the characterization of modified lysine residues by means of both chromatographic retention and liquid scintillation counting.
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PMID:Analytical strategy for determination of active site sequences in aminoacyl-tRNA synthetases. 283 97

The urea denaturation of sperm whale myoglobin and thermal denaturation of ribonuclease have been studied by following the associated volume changes by size-exclusion chromatography on a Toya Soda TSK 3000SW gel permeation column. The permeation properties of the gel have been shown to be invariant in the following solvent systems: 0.2 M NaCl; 8.0 M urea-0.2 M NaCl; and 6.0 M guanidinium chloride ( GdmCl ). A precise measurement of the volume changes associated with solvent-induced protein denaturation is thus practicable. The column was calibrated in the above solvent systems by using 12 well-characterized proteins as standards. In the case of the denaturation of myoglobin by urea, the rate of equilibration of folded and unfolded species is slow on the time scale of the chromatographic experiment, and the two forms are well separated on the column in the transition region. Both the folded and unfolded species are shown to undergo significant swelling in urea. This result suggests that the view of denaturation based solely on the preferential solvation of the unfolded protein is incorrect. The rate of interconversion between folded and unfolded ribonuclease is fast relative to the time scale of the chromatographic experiments performed in this study. This is reflected in the fact that only one peak is observed in the elution profiles of ribonuclease in the transition region. Thermally unfolded ribonuclease has a smaller volume than the unfolded state in urea or GdmCl , suggesting that it has residual structure. The van't Hoff delta H for the thermal unfolding of ribonuclease calculated from the size-exclusion chromatographic experiments (36 +/- 3 kcal/mol) is significantly lower than previously reported values.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Use of high-speed size-exclusion chromatography for the study of protein folding and stability. 672 29

We present a new method for the analysis of glycans enzymatically released from monoclonal antibodies (MAbs) employing a zwitterionic-type hydrophilic interaction chromatography (ZIC-HILIC) column coupled with electrospray ionization mass spectrometry (ESI-MS). Both native and reduced glycans were analyzed, and the developed procedure was compared with a standard HILIC procedure used in the pharmaceutical industry whereby fluorescent-labeled glycans are analyzed using a TSK Amide-80 column coupled with fluorescence detection. The separation of isobaric alditol oligosaccharides present in monoclonal antibodies and ribonuclease B is demonstrated, and ZIC-HILIC is shown to have good capability for structural recognition. Glycan profiles obtained with the ZIC-HILIC column and ESI-MS provided detailed information on MAb glycosylation, including identification of some less abundant glycan species, and are consistent with the profiles generated with the standard procedure. This new ZIC-HILIC method offers a simpler and faster approach for glycosylation analysis of therapeutic antibodies.
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PMID:Glycan profiling of monoclonal antibodies using zwitterionic-type hydrophilic interaction chromatography coupled with electrospray ionization mass spectrometry detection. 2088 7