Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.31.1 (micrococcal nuclease)
 2,818 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Nucleolar organizer region (NOR) silver staining was applied to sections of fixed material. A positive reaction on cryo-ultrathin sections was found as well as on semithin and ultrathin Lowicryl sections. Repeatable staining that was easy to control was obtained by a one-step procedure after aldehyde-Carnoy fixation. Fixation of the material by formaldehyde and glutaraldehyde alone in cacodylate buffer also maintained reaction selectivity when ammonium chloride was used after fixation. Enzymatic digestion by pronase, RNase A, DNase I, or micrococcal nuclease was applied to ultrathin Lowicryl sections. Pronase digestion removed the silver-stained proteins, whereas digestion by the nucleases did not. A routine procedure is proposed for easy NOR silver staining of sections that preserves a good tissue ultrastructure and is also compatible with cytochemical and immunological investigations.
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PMID:Silver staining of the nucleolar organizer regions (NORs) on Lowicryl and cryo-ultrathin sections. 258 Aug 79

With increasing purification of the androgen receptor from nuclei of rat ventral prostate, a receptor-like protein could be demonstrated by chemical staining with silver nitrate. After sonication and digestion of nuclei with micrococcal nuclease, the solubilized receptor was applied to a column of Matrex Gel Green A and eluted with a linear gradient of 0-2 M NaCl. Characterized by specific binding of dihydrotestosterone, this form of the receptor was also androgen dependent and yielded an apparent Mr of 33,000 when analyzed by polyacrylamide gel electrophoresis and silver nitrate staining. To facilitate recovery following chromatography, the receptor was precipitated with 0-40% ammonium sulfate. Analysis of the 15-fold enriched fraction by sucrose density-gradient centrifugation confirmed the presence of a 3S androgen-binding protein. About 200 ng of the precipitated protein was applied to a column of dihydrotestosterone-17 beta-succinyl agarose (ligand concentration, 0.25 mumol/ml). The fractions eluted with 50 microM dihydrotestosterone were electrophoresed and stained as before; again, the presence of a 33,000 Mr protein sensitive to castration was demonstrated. Alternatively, when the precipitated protein was fractionated by fast protein liquid chromatography utilizing a Superose 12 HR 10/30 column, the receptor coeluted with nuclear proteins in the 29,000-36,000 Mr range as determined both by retention time and electrophoresis. In combination, the above methods may be used to obtain a receptor protein purified to near homogeneity with a yield of 5-10%. The amount of receptor afforded by the purification sequence is small but nevertheless sufficient for chemical detection. We anticipate that with modification, the procedures may prove suitable for the recovery of nuclear androgen receptor on a preparative scale.
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PMID:Chemical demonstration of nuclear androgen receptor following affinity chromatography with immobilized ligands. 358 12

Non-histone protein fraction NHCP1 of micrococcal nuclease-sensitive and nuclease-resistant chromatin from Kirkman-Robbins hepatoma and hamster liver was studied by two-dimensional electrophoresis followed by Coomassie and silver staining and by microcomplement fixation technique in the presence of antibodies elicited against NHCP1 of both tissues. Apart from many common spots several tissue specific components associated with either nuclease-sensitive or nuclease-resistant chromatin were found. The presence of tissue specific components among NHCP1 from hepatoma and liver was confirmed by immunological analysis. It was stated that these components are exclusively localized in nuclease-resistant part of chromatin from neoplastic and normal tissues thus suggesting their structural function.
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PMID:Molecular and functional diversity of non-histone protein fraction NHCP1 from hamster Kirkman-Robbins hepatoma and liver. 377 86

This study has examined an approach to searching for specific proteins associated with the altered nucleosome structure of transcriptionally active genes that are induced by steroid hormones in the hen oviduct. Hen oviduct nuclei were digested with micrococcal nuclease by the procedure which selectively excises nucleosomes from the ovalbumin gene. The oviduct nuclei, as well as chick erythrocyte nuclei, were also digested with DNAase I under conditions preferentially sensitive to the ovalbumin gene, as well as the globin gene. Released proteins were characterized by one- and two-dimensional polyacrylamide gel electrophoresis with detection by silver staining. Thus, high mobility group (HMG) proteins 14 and 17 were found in the three cases of nuclease digestion. Furthermore, about 10, 20 and 15 nonhistone protein spots, specific to each nuclease action, were observed in the cases of micrococcal nuclease to oviduct nuclei and DNAase I to oviduct and erythrocyte nuclei, respectively. Between these three series of protein spots, at least three spots were characterized to be common to those released by both nucleases from oviduct nuclei. These common proteins may be involved, as estrogen receptor proteins or others, in recognition of the ovalbumin DNA sequences, followed by a non-sequence-specific process in which the HMG proteins alter the structure of nucleosomes along the transcription unit.
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PMID:An approach to searching for specific proteins associated with active genes in hen oviduct. 651 30

A method for preparation of the morphologically intact synaptonemal complex from rat pachytene spermatocytes is described. Pachytene spermatocytes were fractionated from rat testicular cells by centrifugal elutriation. Nuclei from fractionated pachytene cells were prepared and extensively digested with micrococcal nuclease. The digested nuclei were sedimented through 20% (w/v) sucrose containing 2 M NaCl by centrifugation. About 10% of total nuclear proteins and 1-2% of total genomic DNA was found to be associated with the residual structure. The residual structure, which contains mainly the synaptonemal complex, but may be still contaminated with other nuclear components including membrane and matrix, was stained with silver and examined under light microscopy. It was found that a silver-staining component of the synaptonemal complex is not grossly different from that in pachytene nuclei not subjected to digestion and extraction. Sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis revealed that virtually all the proteins in the residual structure are non-histones. The DNA isolated from the residual structure was about 135 base pairs (bp), long. The DNA was end-labeled and hybridized with a large excess of sonicated rat genomic DNA. The hybridization displayed a kinetics virtually identical to that of total nuclear DNA. We also prepared restricted DNA fragments associated with the residual structure. Southern blot analyses using a probe made from a recombinant DNA clone containing the albumin gene revealed that the DNA associated with the residual structure was not enriched (or depleted) in this gene sequence. Our results strongly suggest that (1) the synaptomenal complex may play a structural role to support the chromatin domains inside pachytene nucleus; and (2) a simple common DNA sequence in the chromatin domain is not required for association with the residual structure which contains morphologically intact synaptonemal complex in rat spermatocytes.
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PMID:Isolation and preliminary characterization of the synaptonemal complex from rat pachytene spermatocytes. 684 Feb 13

Chemical composition of liver chromatin was determined for rats fed a complete stock diet, or a diet lacking protein or fat. High carbohydrate, fat-free (diet 1) and low carbohydrate, protein-free (diet 2) diets were selected because they elicit structural alteration in chromatin as measured by incubation with micrococcal nuclease (E.C. 3.1.4.7). In the present study, either dietary treatment caused an increase in mass ratios of RNA:DNA and nonhistone:DNA, relative to control ratios. The nonhistone-DNA ratios in liver of rats fed diet 1 or diet 2 were 2.4-fold and 3.5-fold, respectively, larger than control ratios. The histone:DNA ratio remained relatively constant among all three dietary treatments. Liver nuclei were purified from rats fed each dietary treatment and were solubilized in 9 M urea. The nuclear proteins were analyzed by two-dimensional electrophoresis and visualized with a silver treatment that stains proteins in color. The electrophoretograms presented show preferentially proteins with low molecular weights and acidic pIs, two characteristics of nonhistones. The two-dimensional protein patterns are nearly identical for nuclear proteins from all three treatments. Analysis of the electrophoretograms indicates that the diet-induced increased nonhistone:DNA ratios are apparently not attributable to new species of protein, but rather to increased relative abundance of many proteins in the existing populations.
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PMID:Analysis of rat liver chromatin and nuclear proteins after nutritional variation 1,2. 708 47

A template-bound RNA polymerase was isolated from Nicotiana clevelandii plants infected with red clover necrotic mosaic dianthovirus (RCNMV) by differential centrifugation, solubilization with dodecyl beta-D-maltopyranoside, and chromatography on columns of Sephacryl S-400 and Q-Sepharose. Analysis of the purified polymerase by SDS-polyacrylamide gel electrophoresis, followed by silver staining or immunoblotting, showed that it contained virus-encoded proteins of molecular masses 27 kDa and 88 kDa together with several minor proteins possibly of host origin. After removal of endogenous RNA with micrococcal nuclease, the polymerase became template-dependent. It was also template-specific, being able to utilize as templates RNA of two strains of RCNMV, but not RNAs of three viruses in different taxonomic groups, namely cucumber mosaic cucumovirus, tomato bushy stunt tombusvirus and tomato mosaic tobamovirus. The products of RNA polymerase reactions were double-stranded RNAs corresponding to RCNMV RNAs 1 and 2. The ability of the template-dependent RNA polymerase to synthesize RNA was completely inhibited by antibodies to a peptide containing the GDD motif, whereas the activity of the template-bound enzyme was unaffected by these antibodies.
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PMID:Isolation and characterization of an RNA-dependent RNA polymerase from Nicotiana clevelandii plants infected with red clover necrotic mosaic dianthovirus. 778 76

Ultraviolet photodissociation (UVPD) has emerged as a promising tool to characterize proteins with regard to not only their primary sequences and post-translational modifications, but also their tertiary structures. In this study, three metal-binding proteins, Staphylococcal nuclease, azurin, and calmodulin, are used to demonstrate the use of UVPD to elucidate metal-binding regions via comparisons between the fragmentation patterns of apo (metal-free) and holo (metal-bound) proteins. The binding of staphylococcal nuclease to calcium was evaluated, in addition to a series of lanthanide(III) ions which are expected to bind in a similar manner as calcium. On the basis of comparative analysis of the UVPD spectra, the binding region for calcium and the lanthanide ions was determined to extend from residues 40-50, aligning with the known crystal structure. Similar analysis was performed for both azurin (interrogating copper and silver binding) and calmodulin (four calcium binding sites). This work demonstrates the utility of UVPD methods for determining and analyzing the metal binding sites of a variety of classes of proteins.
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PMID:Structural Evaluation of Protein/Metal Complexes via Native Electrospray Ultraviolet Photodissociation Mass Spectrometry. 3227 26