Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ebselen (2-phenyl-1,2-benzisoselenazol-3(2H)-one) is a selenium-containing heterocyclic compound, transported bound to albumin in blood. In this report, we demonstrate the transfer of ebselen from its albumin complex to rat liver cytosolic glutathione-S-transferase (GST) and microsomal proteins, as compared to papain. Free ebselen binds to the sulfhydryl groups of proteins, such as GST and papain [Nikawa, T., Schuch, G., Wagner, G. & Sies, H. Biochem. Pharmacol. (in press)]. 2-Mercaptoethanol and N-ethylmaleimide interfere with ebselen binding to microsomal proteins, suggesting that ebselen also binds to the sulfhydryl groups of microsomal proteins. Ebselen is transferred from its albumin complex to rat liver cytosolic GST and microsomal proteins, but not to papain. These results suggest the possibility that ebselen is transferred from albumin to other proteins using their sulfhydryl groups in vivo.
Biochem Mol Biol Int 1994 Feb
PMID:Interaction of albumin-bound ebselen with rat liver glutathione S-transferase and microsomal proteins. 801 34

Lysis of papain-treated group A and B erythrocytes by human complement was studied by an anti-A (BRIC. 131) and an anti-B (BRIC. 30) IgM monoclonal antibody in 51Cr release assays. The indirect effect of membrane-bound antibody, i.e. its influence on complement binding to sensitized surrounding cells, was examined in a cold target competition test in which sensitized, non-labelled cells are present along with sensitized labelled cells and complement. The mode by which anti-A antibodies indirectly suppressed lysis of sensitized B cells up to 20-fold was studied by following C1q and C3b binding. C1q binding to both types of erythrocytes was not altered in mixed populations of erythrocytes in the presence of both antibodies. Binding of C3b to a mixture of both cell types was, however, suppressed, when both antibodies were present. C3b deposition in mixed cell populations did not reach a significantly higher extent than deposited to one type of erythrocyte alone. This was consistent with the results from competitive lysis and suggests that the anti-A captured most C3b at high anti-A concentrations and deprived the similarly sensitized B erythrocytes of complement. We think that this phenomenon is not due to an uneven removal of complement regulatory proteins from A and B erythrocytes by papain. Instead, the phenomenon might be due to an inherent property of anti-A mAb to better produce nucleation sites for C3 convertases which, upon binding factor B, better compete for the limiting factor D. A mathematical analysis of cold target competition experiment (containing 2430 individual measurements) also shows that the distribution of complement between the competing A and B erythrocyte population is uneven, since it predicts that in any given antibody combination the majority of complement is bound to A erythrocytes. This is consistent with the measured average percentage of lysis.
Mol Immunol 1994 Aug
PMID:An indirect effect of an antibody on complement deposition and lysis of differently sensitized surrounding cells. 806 73

The effect of interleukin (IL)-1 beta on proteoglycan (PG) synthesis and secretion, into culture medium by normal human skin and post-burn human normal scar using tissue explants in culture, was investigated. Following exposure of different tissues to labeling with Na2[35SO4] in the presence and absence of IL-1 beta, the extractable [35SO4]PG (isolated from 0.15 M NaCl and 4 M Gdm. Cl extracts), non-extractable [35SO4]PG (isolated after papain treatment of residual tissue), and [35SO4]PG secreted into culture medium were analyzed for contents and distribution. The contents of [35SO4]PG as measured by [35SO4] incorporation indicate differences in [35SO4]PG production of extractable and non-extractable PGs and also in the PGs released into the culture medium. Examination of the sizes of [35SO4]PGs on Sepharose CL-6 beta columns with and without treatment of IL-1 beta shows that the size of non-extractable [35SO4]PG decreases after IL-1 beta treatment. Cellulose acetate plate electrophoresis of these [35SO4]PG fractions shows that the distribution of PGs alters after treatment with IL-1 beta. These results indicate that burn wound healing abnormalities (scarring) is related to a change in the level of PGs, and may be modified by IL-1 beta treatment.
Biochem Mol Biol Int 1993 Nov
PMID:Comparison of the effects of interleukin-1 beta on proteoglycan synthesis by human skin and post-burn normal scar explant cultures. 811 32

Three forms of cellobiohydrolase I (CBH I) (65, 58 and 54 kDa) were isolated to apparent homogeneity from culture filtrates of Trichoderma reesei. The N-terminal sequence of amino acid residues is the same for all of them. The 65 kDa CBH I (pI 4.1) is the intact protein which is fully active against small, soluble substrates and an insoluble substrate Avicel. The 58 kDa CBH I (pI 3.8) and 54 kDa CBH I (pI 3.6) are two truncated forms of the intact CBH I, which are fully active against small, soluble substrates, but have decreased adsorption on and activity against Avicel. Limited proteolysis of the 65 kDa and 58 kDa CBH I by papain yields the same core protein (pI 3.6, 54 kDa). It appears that there are mainly two different specific proteolytic cleavage points in the intact CBH I, one the site for a papain-like protease action cutting at the hinge area (54 kDa CBH I) and the other in the B block (58 kDa CBH I).
Biochem Mol Biol Int 1993 Aug
PMID:Three forms of cellobiohydrolase I from Trichoderma reesei. 822 Feb 39

The structural model derived from X-ray crystallography for unphosphorylated wild-type chicken cystatin is compared with two chicken cystatin structures derived from NMR spectroscopy: the phosphorylated wild-type and the genetically engineered variant AEF-SIM-M29I-M89L. The comparison shows the same overall fold, but also significant differences in structurally variable segments of the polypeptide chain. The largest such segment, comprising residues 71 to 89, is a region characteristic of the family 2 cystatin inhibitors which contains a disulphide bridge (71-81) and the phosphorylation site (Ser80) discussed in the accompanying article. In the crystal structure, the segment 71 to 76 is found as a flexible loop, 77 to 85 as an alpha-helical segment, and 86 to 89 is completely undefined. The solution NMR structures on the other hand are disordered in the initial segment 72 to 80, have an extended conformation at 81 to 83 in contact with the beta-sheet, and clearly show a beta-turn at residues 87 to 90. The segment comprising residues 53 to 57, with smaller variability, is of particular interest as the hairpin loop conserved throughout the cystatin superfamily which binds to the cysteine proteinase. In most of the solution NMR structures, this segment adopts a conformation more like that of stefin B, a family 1 cystatin inhibitor, as was observed in the crystal structure of its inhibitory complex with papain. The differences between the structures are rationalized by an examination of the crystal contacts generated by hypothetical crystal packing of the NMR structures. Additionally, the X-ray refinement shows evidence of conformational disorder in the crystal. Joint refinement with NOE restraints and reflection data does not produce a structure to satisfy the restraints of both methods.
J Mol Biol 1993 Dec 20
PMID:Conformational variability of chicken cystatin. Comparison of structures determined by X-ray diffraction and NMR spectroscopy. 826 13

Despite the rapid mutational change that is typical of positive-strand RNA viruses, enzymes mediating the replication and expression of virus genomes contain arrays of conserved sequence motifs. Proteins with such motifs include RNA-dependent RNA polymerase, putative RNA helicase, chymotrypsin-like and papain-like proteases, and methyltransferases. The genes for these proteins form partially conserved modules in large subsets of viruses. A concept of the virus genome as a relatively evolutionarily stable "core" of housekeeping genes accompanied by a much more flexible "shell" consisting mostly of genes coding for virion components and various accessory proteins is discussed. Shuffling of the "shell" genes including genome reorganization and recombination between remote groups of viruses is considered to be one of the major factors of virus evolution. Multiple alignments for the conserved viral proteins were constructed and used to generate the respective phylogenetic trees. Based primarily on the tentative phylogeny for the RNA-dependent RNA polymerase, which is the only universally conserved protein of positive-strand RNA viruses, three large classes of viruses, each consisting of distinct smaller divisions, were delineated. A strong correlation was observed between this grouping and the tentative phylogenies for the other conserved proteins as well as the arrangement of genes encoding these proteins in the virus genome. A comparable correlation with the polymerase phylogeny was not found for genes encoding virion components or for genome expression strategies. It is surmised that several types of arrangement of the "shell" genes as well as basic mechanisms of expression could have evolved independently in different evolutionary lineages. The grouping revealed by phylogenetic analysis may provide the basis for revision of virus classification, and phylogenetic taxonomy of positive-strand RNA viruses is outlined. Some of the phylogenetically derived divisions of positive-strand RNA viruses also include double-stranded RNA viruses, indicating that in certain cases the type of genome nucleic acid may not be a reliable taxonomic criterion for viruses. Hypothetical evolutionary scenarios for positive-strand RNA viruses are proposed. It is hypothesized that all positive-strand RNA viruses and some related double-stranded RNA viruses could have evolved from a common ancestor virus that contained genes for RNA-dependent RNA polymerase, a chymotrypsin-related protease that also functioned as the capsid protein, and possibly an RNA helicase.
Crit Rev Biochem Mol Biol 1993
PMID:Evolution and taxonomy of positive-strand RNA viruses: implications of comparative analysis of amino acid sequences. 826 9

The effect of different protease inhibitors on the proteolytic processing of the plum pox potyvirus (PPV) polyprotein has been analyzed. Human cystatin C, an inhibitor of cysteine proteases, interfered with the autoprocessing of the viral papain-like cysteine protease HCPro. Unexpectedly, it also had an inhibitory effect on the autocatalytic cleavage of the Nla protease which, although it has a Cys residue in its active center, has been described as structurally related to serine proteases. Other protease inhibitors tested had no effect on any of the cleavage events analyzed.
Plant Mol Biol 1993 Jul
PMID:Inhibitory effects of human cystatin C on plum pox potyvirus proteases. 834 5

The C-terminal 24-kDa fragment of myosin subfragment-1 (S-1) heavy chain was isolated by papain digestion of porcine aorta myosin followed by ethanol fractionation. The isolated 24-kDa fragment was digested by lysylendopeptidase. When the digest was ultracentrifuged with F-actin, 7- and 2-kDa peptides coprecipitated with the actin. These two peptides were isolated by high performance liquid chromatography, and their amino acid sequences were determined. The 7- and 2-kDa peptides correspond to residues 692-744 and 835-846, respectively, of the chicken gizzard myosin heavy chain (Yanagisawa, M., Hamada, Y., Katsuragawa, Y., Imamura, M., Mikawa, T., and Masaki, T. (1987) J. Mol. Biol. 198, 143-157). The 7-kDa peptide contains the reactive cysteine residues, SH1 and SH2. The isolated 7- and 2-kDa peptides also bound to F-actin with dissociation constants of 0.6 and 12 microM, respectively. The 2-kDa peptide was found to compete with rabbit skeletal S-1 for the binding to F-actin by examining the binding of S-1 to actin in the presence of various concentrations of the 2-kDa peptide. The 2-kDa peptide was also shown to interact with the regulatory light chain of aorta myosin by difference UV absorption spectroscopy. The 2-kDa peptide inhibited the actin-activated ATPase activity of skeletal S-1, and the inhibition was canceled by the addition of the isolated regulatory light chain. These results suggest that the newly found 2-kDa peptide region may be related to the regulation of smooth muscle actomyosin ATPase activity by phosphorylation of the regulatory light chain.
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PMID:Actin-binding peptides obtained from the C-terminal 24-kDa fragment of porcine aorta smooth muscle myosin subfragment-1 heavy chain. 842 12

Expression of cysteine proteinase inhibitors (cystatins) in tobacco or other plants has the potential for improving resistance against pathogens and insects that possess cysteine proteinases. A chimeric gene containing a cDNA clone of rice cystatin (oryzacystatin-I; OC-I), the cauliflower mosaic virus 35S promoter, and the nopaline synthase 3' region was introduced into tobacco plants by Agrobacterium tumefaciens. The presence of the chimeric gene in transgenic plants was detected by a polymerase chain reaction-amplified assay, and transcriptional activity was shown by RNA blot analysis. Heated extracts from transgenic tobacco plants, as well as from progeny which were obtained by selfing a primary transformant, contained protein bands that corresponded in molecular mass to OC-I and reacted with antibodies raised against rOC, a recombinant OC-I protein produced by Escherichia coli. Similar bands were absent in extracts from untransformed control plants. OC-I levels reached 0.5% and 0.6% of the total soluble proteins in leaves and roots, respectively, of some progeny. On a fresh weight basis, the OC-I content was higher in leaves (50 micrograms/g) than in roots (30 micrograms/g). OC-I was partially purified from protein extracts of rice seeds and from transgenic tobacco leaves by affinity to anti-rOC antibodies. OC-I from both sources was active against papain.
Plant Mol Biol 1993 Feb
PMID:Expression of a cysteine proteinase inhibitor (oryzacystatin-I) in transgenic tobacco plants. 844 64

The major source of amino acids for insect embryos are yolk proteins which accumulate in developing oocytes and are hydrolyzed during embryogenesis. Studies on Musca domestica embryogenesis indicated that a cathepsin B-like proteinase is responsible for yolk protein degradation (Ribolla et al., 1993). In this study, we report the purification of mature cathepsin and show that it is made up of a single 41 kDa polypeptide chain. The Musca domestica cathepsin NH2-terminal 11-residue sequence was determined (Ala-Pro-Lys-Tyr-Val-Asp-Tyr-Gly-Glu-Asn-Glu) and reveals homology with other cathepsins of the papain family. Experiments using serum anti-cathepsin show that the enzyme is stored in oocytes as a 55 kDa zymogen. The activation of the zymogen occurs in vitro only at low pH. In vitro activation in the presence of cysteine protease inhibitors is blocked at an intermediary polypeptide of 48 kDa. Kinetic studies of this activation process at pH 3.5 and 4.6 show that the zymogen is processed in a manner similar to that of pepsin (Foltmann, 1986) and papain (Vernet et al., 1991). We propose that Musca domestica cathepsin zymogen activation occurs in two steps. First, an intramolecular cleavage of the procathepsin polypeptide chain (55,000), induced by low pH gives rise to an intermediary polypeptide (48,000) which then undergoes autolysis to produce the mature enzyme (41,000).
Insect Biochem Mol Biol 1995 Oct
PMID:Processing of procathepsin from Musca domestica eggs. 854 83


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