- MeSH
- avidin diagnostické užití MeSH
- biosenzitivní techniky metody přístrojové vybavení využití MeSH
- biotin diagnostické užití MeSH
- bromkyan diagnostické užití MeSH
- epichlorhydrin diagnostické užití MeSH
- glutaraldehyd diagnostické užití MeSH
- karbodiimidy diagnostické užití MeSH
- klinické laboratorní techniky trendy využití MeSH
- kyselina jodistá diagnostické užití MeSH
- makromolekulární látky izolace a purifikace MeSH
- merkaptamin diagnostické užití MeSH
- nanočástice diagnostické užití MeSH
- polysacharidy diagnostické užití MeSH
- streptavidin diagnostické užití MeSH
- sukcinimidy diagnostické užití MeSH
Retroviral proteases are translated as a part of Gag-related polyproteins, and are released and activated during particle release. Mason-Pfizer monkey virus (M-PMV) Gag polyproteins assemble into immature capsids within the cytoplasm of the host cells; however, their processing occurs only after transport to the plasma membrane and subsequent release. Thus, the activity of M-PMV protease is expected to be highly regulated during the replication cycle. It has been proposed that reversible oxidation of protease cysteine residues might be responsible for such regulation. We show that cysteine residues in M-PMV protease can form an intramolecular S-S bridge. The disulfide bridge shifts the monomer/dimer equilibrium in favor of the dimer, and increases the proteolytic activity significantly. To investigate the role of this disulfide bridge in virus maturation and replication, we engineered an M-PMV clone in which both protease cysteine residues were replaced by alanine (M-PMV(PRC7A/C106A)). Surprisingly, the cysteine residues were dispensable for Gag polyprotein processing within the virus, indicating that even low levels of protease activity are sufficient for polyprotein processing during maturation. However, the long-term infectivity of M-PMV(PRC7A/C106A) was noticeably compromised. These results show clearly that the proposed redox mechanism does not rely solely on the formation of the stabilizing S-S bridge in the protease. Thus, in addition to the protease disulfide bridge, reversible oxidation of cysteine and/or methionine residues in other domains of the Gag polyprotein or in related cellular proteins must be involved in the regulation of maturation.
- MeSH
- bromkyan metabolismus MeSH
- Cercopithecus aethiops MeSH
- COS buňky MeSH
- cystein metabolismus MeSH
- dimerizace MeSH
- disulfidy metabolismus MeSH
- endopeptidasy chemie metabolismus ultrastruktura MeSH
- financování organizované MeSH
- fluorescenční spektrometrie MeSH
- genové produkty gag metabolismus MeSH
- kinetika MeSH
- Masonův-Pfizerův opičí virus enzymologie fyziologie MeSH
- molekulární sekvence - údaje MeSH
- molekulová hmotnost MeSH
- mutantní proteiny chemie metabolismus MeSH
- nukleární magnetická rezonance biomolekulární MeSH
- posttranslační úpravy proteinů MeSH
- replikace viru fyziologie MeSH
- retrovirové infekce MeSH
- sekvence aminokyselin MeSH
- sekvenční seřazení MeSH
- stabilita enzymů MeSH
- termodynamika MeSH
- virion fyziologie MeSH
- vztahy mezi strukturou a aktivitou MeSH
- zvířata MeSH
- Check Tag
- zvířata MeSH
Several new biocompatible and degradable materials were prepared by chemical modification of sodium hyaluronate. The method of activation of hyaluronate by cyanogen bromide was used and subsequent reaction with nucleophile led to the formation of carbamate. This modification of hydroxyl groups of glycosaminoglycans preserves the carboxyl groups and retains properties of polyelectrolyte. This method affords derivatives easily and the reaction condition correlates with degree of substitution. The experimental results show the effect of reaction conditions (reaction time, ratio of reactants) and effect of substitution on biodegradability. The obtained materials were characterized by nuclear magnetic resonance and Fourier transform infrared spectroscopy. Copyright (c) 2006 Wiley Periodicals, Inc.
- MeSH
- biodegradace MeSH
- biokompatibilní materiály chemická syntéza MeSH
- bromkyan chemie MeSH
- financování organizované MeSH
- gelová chromatografie MeSH
- glykosaminoglykany chemie MeSH
- hyaluronoglukosaminidasa farmakologie MeSH
- hydroxylový radikál chemie MeSH
- karbamáty chemická syntéza MeSH
- kinetika MeSH
- kyselina hyaluronová chemická syntéza chemie MeSH
- nukleární magnetická rezonance biomolekulární MeSH
- rozpustnost MeSH
- skot MeSH
- spektroskopie infračervená s Fourierovou transformací MeSH
- viskozita MeSH
- voda chemie MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- skot MeSH
- zvířata MeSH
Binding of lead (as lead acetate) to collagen type I alpha, and alpha2 chains, collagen type V and a large cyanogen bromide fragment of type I collagen [alpha2(I)CB(3,5)] was investigated by the large-zone Hummel-Dreyer method. It was demonstrated that two categories of binding sites exist in the collagen molecule, the number of which correlates rather well with the available aspartic and glutamic acid residues. Similar results were obtained for all collagen chains (fragments) used. The number of sites thus obtained was compared with the cross-striation pattern (reflecting areas where lead is bound) of the SLS form of collagen type I (alpha1 chain); it is suggested that the number of bands seen in the SLS form reflects primarily the number of available aspartic acid residues in the molecule. The association constants obtained are comparable with the low affinity interactions seen e.g., between Cu and bovine serum albumin.
