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Haseltine C, Montalvo-Rodriguez R, Carl A, Bini E, Blum P. Extragenic pleiotropic mutations that repress glycosyl hydrolase expression in the hyperthermophilic archaeon Sulfolobus solfataricus. Genetics 1999; 152:1353-61. [PMID: 10430566 PMCID: PMC1460713 DOI: 10.1093/genetics/152.4.1353] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The hyperthermophilic archaeon Sulfolobus solfataricus employs a catabolite repression-like regulatory system to control enzymes involved in carbon and energy metabolism. To better understand the basis of this system, spontaneous glycosyl hydrolase mutants were isolated using a genetic screen for mutations, which reduced expression of the lacS gene. The specific activities of three glycosyl hydrolases, including an alpha-glucosidase (malA), a beta-glycosidase (lacS), and the major secreted alpha-amylase, were measured in the mutant strains using enzyme activity assays, Western blot analysis, and Northern blot analysis. On the basis of these results the mutants were divided into two classes. Group I mutants exhibited a pleiotropic defect in glycosyl hydrolase expression, while a single group II mutant was altered only in lacS expression. PCR, Southern blot analysis, comparative heterologous expression in Escherichia coli, and DNA sequence analysis excluded cis-acting mutations as the explanation for reduced lacS expression in group I mutants. In contrast lacS and flanking sequences were deleted in the group II mutant. Revertants were isolated from group I mutants using a lacS-specific screen and selection. These revertants were pleiotropic and restored glycosyl hydrolase activity either partially or completely to wild-type levels as indicated by enzyme assays and Western blots. The lacS mutation in the group II mutant, however, was nonrevertible. The existence of group I mutants and their revertants reveals the presence of a trans-acting transcriptional regulatory system for glycosyl hydrolase expression.
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Haseltine C, Montalvo-Rodriguez R, Bini E, Carl A, Blum P. Coordinate transcriptional control in the hyperthermophilic archaeon Sulfolobus solfataricus. J Bacteriol 1999; 181:3920-7. [PMID: 10383958 PMCID: PMC93880 DOI: 10.1128/jb.181.13.3920-3927.1999] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The existence of a global gene regulatory system in the hyperthermophilic archaeon Sulfolobus solfataricus is described. The system is responsive to carbon source quality and acts at the level of transcription to coordinate synthesis of three physically unlinked glycosyl hydrolases implicated in carbohydrate utilization. The specific activities of three enzymes, an alpha-glucosidase (malA), a beta-glycosidase (lacS), and an alpha-amylase, were reduced 4-, 20-, and 10-fold, respectively, in response to the addition of supplementary carbon sources to a minimal sucrose medium. Western blot analysis using anti-alpha-glucosidase and anti-beta-glycosidase antibodies indicated that reduced enzyme activities resulted exclusively from decreased enzyme levels. Northern blot analysis of malA and lacS mRNAs revealed that changes in enzyme abundance arose primarily from reductions in transcript concentrations. Culture conditions precipitating rapid changes in lacS gene expression were established to determine the response time of the regulatory system in vivo. Full induction occurred within a single generation whereas full repression occurred more slowly, requiring nearly 38 generations. Since lacS mRNA abundance changed much more rapidly in response to a nutrient down shift than to a nutrient up shift, transcript synthesis rather than degradation likely plays a role in the regulatory response.
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Teter SA, Houry WA, Ang D, Tradler T, Rockabrand D, Fischer G, Blum P, Georgopoulos C, Hartl FU. Polypeptide flux through bacterial Hsp70: DnaK cooperates with trigger factor in chaperoning nascent chains. Cell 1999; 97:755-65. [PMID: 10380927 DOI: 10.1016/s0092-8674(00)80787-4] [Citation(s) in RCA: 299] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
A role for DnaK, the major E. coli Hsp70, in chaperoning de novo protein folding has remained elusive. Here we show that under nonstress conditions DnaK transiently associates with a wide variety of nascent and newly synthesized polypeptides, with a preference for chains larger than 30 kDa. Deletion of the nonessential gene encoding trigger factor, a ribosome-associated chaperone, results in a doubling of the fraction of nascent polypeptides interacting with DnaK. Combined deletion of the trigger factor and DnaK genes is lethal under normal growth conditions. These findings indicate important, partially overlapping functions of DnaK and trigger factor in de novo protein folding and explain why the loss of either chaperone can be tolerated by E. coli.
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Fisher A, Von Herzen R, Blum P, Hoppie B, Wang K. Evidence may indicate recent warming of shallow slope bottom water off New Jersey shore. ACTA ACUST UNITED AC 1999. [DOI: 10.1029/99eo00117] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Rolfsmeier M, Haseltine C, Bini E, Clark A, Blum P. Molecular characterization of the alpha-glucosidase gene (malA) from the hyperthermophilic archaeon Sulfolobus solfataricus. J Bacteriol 1998; 180:1287-95. [PMID: 9495770 PMCID: PMC107019 DOI: 10.1128/jb.180.5.1287-1295.1998] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/1997] [Accepted: 12/12/1997] [Indexed: 02/06/2023] Open
Abstract
Acidic hot springs are colonized by a diversity of hyperthermophilic organisms requiring extremes of temperature and pH for growth. To clarify how carbohydrates are consumed in such locations, the structural gene (malA) encoding the major soluble alpha-glucosidase (maltase) and flanking sequences from Sulfolobus solfataricus were cloned and characterized. This is the first report of an alpha-glucosidase gene from the archaeal domain. malA is 2,083 bp and encodes a protein of 693 amino acids with a calculated mass of 80.5 kDa. It is flanked on the 5' side by an unusual 1-kb intergenic region. Northern blot analysis of the malA region identified transcripts for malA and an upstream open reading frame located 5' to the 1-kb intergenic region. The malA transcription start site was located by primer extension analysis to a guanine residue 8 bp 5' of the malA start codon. Gel mobility shift analysis of the malA promoter region suggests that sequences 3' to position -33, including a consensus archaeal TATA box, play an essential role in malA expression. malA homologs were detected by Southern blot analysis in other S. solfataricus strains and in Sulfolobus shibatae, while no homologs were evident in Sulfolobus acidocaldarius, lending further support to the proposed revision of the genus Sulfolobus. Phylogenetic analyses indicate that the closest S. solfataricus alpha-glucosidase homologs are of mammalian origin. Characterization of the recombinant enzyme purified from Escherichia coli revealed differences from the natural enzyme in thermostability and electrophoretic behavior. Glycogen is a substrate for the recombinant enzyme. Unlike maltose hydrolysis, glycogen hydrolysis is optimal at the intracellular pH of the organism. These results indicate a unique role for the S. solfataricus alpha-glucosidase in carbohydrate metabolism.
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Rockabrand D, Livers K, Austin T, Kaiser R, Jensen D, Burgess R, Blum P. Roles of DnaK and RpoS in starvation-induced thermotolerance of Escherichia coli. J Bacteriol 1998; 180:846-54. [PMID: 9473038 PMCID: PMC106963 DOI: 10.1128/jb.180.4.846-854.1998] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
DnaK is essential for starvation-induced resistance to heat, oxidation, and reductive division in Escherichia coli. Studies reported here indicate that DnaK is also required for starvation-induced osmotolerance, catalase activity, and the production of the RpoS-controlled Dps (PexB) protein. Because these dnaK mutant phenotypes closely resemble those of rpoS (sigma38) mutants, the relationship between DnaK and RpoS was evaluated directly during growth and starvation at 30 degrees C in strains with genetically altered DnaK content. A starvation-specific effect of DnaK on RpoS abundance was observed. During carbon starvation, DnaK deficiency reduced RpoS levels threefold, while DnaK excess increased RpoS levels nearly twofold. Complementation of the dnaK mutation restored starvation-induced RpoS levels to normal. RpoS deficiency had no effect on the cellular concentration of DnaK, revealing an epistatic relationship between DnaK and RpoS. Protein half-life studies conducted at the onset of starvation indicate that DnaK deficiency significantly destabilized RpoS. RpoH (sigma32) suppressors of the dnaK mutant with restored levels of RpoS and dnaK rpoS double mutants were used to show that DnaK plays both an independent and an RpoS-dependent role in starvation-induced thermotolerance. The results suggest that DnaK coordinates sigma factor levels in glucose-starved E. coli.
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Blum P. [Thoughts of a (relatively) unknown beauty]. DER HAUTARZT 1998; 49:145-6. [PMID: 9551340 DOI: 10.1007/s001050050717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Quiñones CR, Hürzeler MB, Schüpbach P, Kirsch A, Blum P, Caffesse RG, Strub JR. Maxillary sinus augmentation using different grafting materials and osseointegrated dental implants in monkeys. Part II. Evaluation of porous hydroxyapatite as a grafting material. Clin Oral Implants Res 1997; 8:487-96. [PMID: 9580408 DOI: 10.1034/j.1600-0501.1997.080607.x] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The aim of this study was to evaluate clinically, histologically and histometrically the use of porous hydroxyapatite (i.e. Interpore-200) as a bone grafting material for maxillary sinus augmentation procedures. In 4 adult male rhesus monkeys (i.e. Macaca mulatta) the 1st, 2nd and 3rd maxillary molars on one side of the jaws were extracted and the remaining bone between the alveolar crest and the bottom of the sinus was reduced to 3-4 mm. After 3 months, maxillary sinus augmentation procedures were performed on one side of the jaws in each monkey, and the sinuses grafted with the porous hydroxyapatite. Two IMZ titanium plasma-sprayed cylinder implants were then immediately placed into the augmented sinus (i.e. simultaneous implants-loaded group). After 4 months, 2 additional similar implants were placed into the previously augmented sinuses (i.e. delayed implants-loaded group). Four months later, the abutment connection was performed and all 4 implants were loaded with a gold-alloy bridge for 6 months (i.e. until sacrifice). The contralateral side of each monkey received the same treatment with the exception that the extractions were performed 7 months after those in the opposite side and that the implants in this side were not loaded. Thus, 2 additional study groups (i.e. simultaneous implants-unloaded group and delayed implants-unloaded group) were obtained. Clinically, all loaded implants were stable at the day of sacrifice. Histologic analysis demonstrated a significant amount of new bone formation in the augmented sinuses. Porous hydroxyapatite graft particles appeared to be integrated to the new bone. The percentage of direct mineralized bone-to-implant contact in the augmented area was greater on the delayed-placed implants than on the simultaneously-placed implants. Also, the percentage of direct mineralized bone-to-implant contact was greater in the residual bone than in the augmented area. It was concluded that this porous hydroxyapatite bone graft enhanced bone formation and bone-to-implant contact in the augmented sinuses and that the delayed implant placement in combination with the sinus augmentation procedure appears to result in a higher percentage of direct mineralized bone-to-implant contact.
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Wooden KK, Hogstrom KR, Blum P, Gastorf RJ, Cox JD. Whole-limb irradiation of the lower calf using a six-field electron technique. Med Dosim 1996; 21:211-8. [PMID: 8985926 DOI: 10.1016/s0958-3947(96)00129-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The present work demonstrates utilization of electron beam irradiation for the treatment of Kaposi's sarcoma when the full circumference of the lower calf is involved, and when the deep lymphatics are negative for disease. The finite penetration of the electron beam spares deep tissue, preventing the edema associated with photon total limb irradiation. The number of fields with fall-off required to produce a uniform dose to a cylindrical anatomic structure was studied by calculating dose distributions resulting from two-, four-, and six-field techniques for a 5-MeV electron beam and a 9 cm diameter cylinder. The dosimetry and set-up for the six-field technique is demonstrated by a case study. Results show that a six-field electron technique produced a sufficiently uniform dose while remaining relatively easy to set up and use to deliver patient treatment. For the patient case study, dose distributions for the six-field technique showed that (1) the penetration of the 90% dose decreased from 1.5 cm for a single field to approximately 1.0 cm for a 5-MeV beam; (2) the surface dose increased from approximately 70% to 100%, (3) the dose around the circumference of the leg at the depth of 1 cm or less varied from approximately 90% to 120% of the prescribed dose; and (4) the prescribed dose was 2.5 times the maximum central-axis dose from a single field. The six-field treatment was relatively simple to apply and produced an acceptable dose distribution for treatment of Kaposi's sarcoma of the lower calf. This treatment should be applicable to other sites such as the thigh and arms and for other cutaneous diseases such as melanoma.
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Haseltine C, Rolfsmeier M, Blum P. The glucose effect and regulation of alpha-amylase synthesis in the hyperthermophilic archaeon Sulfolobus solfataricus. J Bacteriol 1996; 178:945-50. [PMID: 8576067 PMCID: PMC177752 DOI: 10.1128/jb.178.4.945-950.1996] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
An alpha-amylase was purified from culture supernatants of Sulfolobus solfataricus 98/2 during growth on starch as the sole carbon and energy source. The enzyme is a homodimer with a subunit mass of 120 kDa. It catalyzes the hydrolysis of starch, dextrin, and alpha-cyclodextrin with similar efficiencies. Addition of exogenous glucose represses production of alpha-amylase, demonstrating that a classical glucose effect is operative in this organism. Synthesis of [35S]-alpha-amylase protein is also subject to the glucose effect. alpha-Amylase is constitutively produced at low levels but can be induced further by starch addition. The absolute levels of alpha-amylase detected in culture supernatants varied greatly with the type of sole carbon source used to support growth. Aspartate was identified as the most repressing sole carbon source for alpha-amylase production, while glutamate was the most derepressing. The pattern of regulation of alpha-amylase production seen in this organism indicates that a catabolite repression-like system is present in a member of the archaea.
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Rockabrand D, Blum P. Multicopy plasmid suppression of stationary phase chaperone toxicity in Escherichia coli by phosphogluconate dehydratase and the N-terminus of DnaK. MOLECULAR & GENERAL GENETICS : MGG 1995; 249:498-506. [PMID: 8544815 DOI: 10.1007/bf00290575] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Overproduction of DnaK in Escherichia coli results in a bacteriocidal effect. This effect is most acute in stationary phase cells. A selection scheme was developed to isolate multicopy suppressors from an E. coli plasmid expression library, which overcome the stationary phase toxicity of excess DnaK. Two suppressor plasmids were recovered which contained inserts of 1.85 kb and 2.69 kb, respectively. Rearranged and deleted plasmid derivatives were constructed and used to further localize the suppressors. DNA sequence analysis demonstrated that one suppressor encoded phosphogluconate dehydratase (Edd) while the other suppressor encoded the N-terminal 237 amino acids of DnaK itself (DnaK'). Strains bearing the suppressor plasmids constitutively overproduced proteins with apparent masses of 66 kDa (Edd) and 37 kDa (DnaK') as determined by gel electrophoresis. Western blot analysis using polyclonal antisera specific for either Edd or DnaK confirmed the identity of these overproduced proteins. Suppression of DnaK toxicity was eliminated by the introduction of a + 1 frameshift mutation early in the respective coding regions of either of the two suppressors. These results suggest that suppressor gene translation plays a role in the mechanism of DnaK suppression.
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Goldstein L, Davis-Amaral E, Blum P, Luer C. The role of anion channels in osmotically activated taurine release from embryonic skate (Raja eglanteria) heart. J Exp Biol 1995; 198:2635-7. [PMID: 9320572 DOI: 10.1242/jeb.198.12.2635] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Taurine, a major osmolyte of vertebrate hearts, is released from the skate heart at increased rates during hypotonic stress. We tested the hypothesis that this taurine release is mediated by chloride channels activated by swelling. Two inhibitors of the channels, NPPB and DIDS, inhibited the volume-activated release of taurine from embryonic skate hearts. These results support the hypothesis that swelling-activated chloride channels mediate the release of cardiac taurine.
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Schmid HR, Schmitter D, Blum P, Miller M, Vonderschmitt D. Lung tumor cells: a multivariate approach to cell classification using two-dimensional protein pattern. Electrophoresis 1995; 16:1961-8. [PMID: 8586071 DOI: 10.1002/elps.11501601322] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
High resolution two-dimensional polyacrylamide gel electrophoresis (2-D PAGE) is a powerful research tool for the analytical separation of cellular proteins. The qualitative and quantitative pattern of polypeptides synthesized by a cell represents its phenotype and thus defines characteristics such as the morphology and the biological behavior of the cell. By analyzing and comparing the protein patterns of different cells it is possible to recognize the cell type and also to identify the most typical features of these cells. In applied pathology it is often difficult to identify the tissue of origin and the stage or grade of a neoplasia by cellular morphology analyzed by classical or immunostaining procedures. The protein pattern itself is the most characteristic feature of a cell and should therefore contribute to the identification of the cell type. For this reason we separated protein fractions originating from different lung tumor cell lines using 2-D PAGE and we compared the resulting patterns on a multivariate statistical level using correspondence analysis (CA) and ascendant hierarchical clustering (AHC). The results indicate that (i) protein patterns are highly typical for cells and that (ii) the comparison of the protein patterns of a set of interesting cell types allows the identification of potentially new marker proteins. 2-D PAGE is thus a unique and powerful tool for molecular cytology or histopathology, unveiling the protein expression level of tissues or cells.
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Rockabrand D, Arthur T, Korinek G, Livers K, Blum P. An essential role for the Escherichia coli DnaK protein in starvation-induced thermotolerance, H2O2 resistance, and reductive division. J Bacteriol 1995; 177:3695-703. [PMID: 7601833 PMCID: PMC177085 DOI: 10.1128/jb.177.13.3695-3703.1995] [Citation(s) in RCA: 51] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
During a 3-day period, glucose starvation of wild-type Escherichia coli produced thermotolerant, H2O2-resistant, small cells with a round morphology. These cells contained elevated levels of the DnaK protein, adjusted either for total protein or on a per-cell basis. Immunoprecipitation of [35S]methionine-labeled protein produced by such starving cells demonstrated that DnaK underwent continuous synthesis but at decreasing rates throughout this time. Glucose resupplementation of starving cells resulted in rapid loss of thermotolerance, H2O2 resistance, and the elevated DnaK levels. A dnaK deletion mutant, but not an otherwise isogenic wild-type strain, failed to develop starvation-induced thermotolerance or H2O2 resistance. The filamentous phenotype associated with DnaK deficiency was suppressed by cultivation in a defined glucose medium. When starved for glucose, the nonfilamentous and rod-shaped dnaK mutant strain failed to convert into the small spherical form typical of starving wild-type cells. The dnaK mutant retained the ability to develop adaptive H2O2 resistance during growth but not adaptive resistance to heat. Complementation of DnaK deficiency by using Ptac-regulated dnaK+ and dnaK+J+ expression plasmids confirmed a specific role for the DnaK molecular chaperone in these starvation-induced phenotypes.
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MESH Headings
- Adaptation, Physiological
- Adhesins, Escherichia coli/genetics
- Adhesins, Escherichia coli/isolation & purification
- Adhesins, Escherichia coli/metabolism
- Antigens, Bacterial/genetics
- Antigens, Bacterial/isolation & purification
- Antigens, Bacterial/metabolism
- Antigens, Surface/genetics
- Antigens, Surface/isolation & purification
- Antigens, Surface/metabolism
- Bacterial Proteins/genetics
- Bacterial Proteins/physiology
- Cell Division
- Drug Resistance, Microbial
- Escherichia coli/cytology
- Escherichia coli/genetics
- Escherichia coli/physiology
- Escherichia coli Proteins
- Fimbriae Proteins
- Genetic Complementation Test
- HSP70 Heat-Shock Proteins/biosynthesis
- HSP70 Heat-Shock Proteins/genetics
- HSP70 Heat-Shock Proteins/physiology
- Hot Temperature/adverse effects
- Hydrogen Peroxide/toxicity
- Mutation
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Blum P. [Reporting occupational disease. A system ready for revision]. TIDSSKRIFT FOR DEN NORSKE LEGEFORENING 1995; 115:490-4. [PMID: 7871510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
The article reviews the system of reporting occupational disease and the reporting pattern over the last ten years. The available information seems to indicate a very low reported incidence of occupational disease. Possible reasons are given. There seems to be a need to simplify our present system and make it more user-friendly. There is also a general need to inform and motivate various user groups, especially general practitioners. In addition, greater collaboration between occupational and public health services may help to increase the reporting of occupational disease in Norway.
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Rolfsmeier M, Blum P. Purification and characterization of a maltase from the extremely thermophilic crenarchaeote Sulfolobus solfataricus. J Bacteriol 1995; 177:482-5. [PMID: 7814342 PMCID: PMC176616 DOI: 10.1128/jb.177.2.482-485.1995] [Citation(s) in RCA: 83] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
A soluble maltase (alpha-glucosidase) with an apparent subunit mass of 80 kDa was purified to homogeneity from Sulfolobus solfataricus. The enzyme liberates glucose from maltose and malto-oligomers. Maximal activity was observed at 105 degrees C, with half-lives of 11 h (85 degrees C), 3.0 h (95 degrees C), and 2.75 h (100 degrees C). The enzyme was generally resistant to proteolysis and denaturants including aliphatic alcohols. n-Propanol treatment at 85 degrees C increased both Km and Vmax for maltose hydrolysis.
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Krska J, Elthon T, Blum P. Monoclonal antibody recognition and function of a DnaK (HSP70) epitope found in gram-negative bacteria. J Bacteriol 1993; 175:6433-40. [PMID: 7691795 PMCID: PMC206751 DOI: 10.1128/jb.175.20.6433-6440.1993] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
The isolation and characterization of a monoclonal antibody (MAb 2G5) specific for the bacterial DnaK (HSP70) protein is described. The 2G5 MAb was initially selected because of its ability to bind to DnaK under denaturing conditions. Isotype analyses indicated that 2G5 was an immunoglobulin G2a. Dose-response Western blot (immunoblot) experiments with purified but unconcentrated 2G5 permitted detection of 10 ng of pure DnaK protein. The DnaK epitope was determined by Western blot analysis of a series of truncated DnaK fragments overproduced in Escherichia coli using 5' and 3' dnaK-deleted expression plasmids. The epitope mapped to a 22-amino-acid region spanning DnaK residues 288 and 310. Phylogenetic distribution of the epitope was examined by Western blot analysis of a wide variety of bacterial species and indicated that the epitope was uniquely present in gram-negative organisms. The proximity of the epitope to the presumed DnaK ATP-binding pocket suggested that MAb binding might inhibit DnaK ATPase activity. In vitro analysis supported this prediction and demonstrated that MAb-mediated inhibition of ATPase activity was antibody specific and occurred at stoichiometric molar ratios of MAb to DnaK. Possible mechanisms to explain the ability of the 2G5 MAb to inhibit DnaK activity are discussed.
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Rockabrand D, Partridge J, Krska J, Blum P. Nucleotide sequence analysis and heterologous expression of the Erysipelothrix rhusiopathiae dnaJ gene. FEMS Microbiol Lett 1993; 111:79-85. [PMID: 8359682 DOI: 10.1111/j.1574-6968.1993.tb06365.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
DNA sequence analysis of chromosomal DNA from the Gram-positive facultative intracellular pathogen, Erysipelothrix rhusiopathiae has identified a dnaJ heat shock gene homolog. A 1109-bp open reading frame encoding dnaJ is located immediately 3' to the E. rhusiopathiae dnaK gene. The deduced DnaJ amino acid sequence exhibits the modular structure of other members of the DnaJ protein class including a glycine-rich region and the repeating consensus sequence CXXCXGXGX. Heterologous expression of the dnaJ sequence in Escherichia coli resulted in accumulation of a unique 38.9-kDa protein with an isoelectric point of 8.0. Deletion analysis of the dnaJ gene was used to confirm that the overproduced protein was encoded by the dnaJ sequence.
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Amsler C, Armstrong DS, Augustin I, Baker CA, Barnett BM, Batty CJ, Beuchert K, Birien P, Bistirlich J, Blum P, Bossingham R, Bossy H, Braune K, Brose J, Bugg DV, Burchell M, Case T, Chung SU, Cooper A, Crowe KM, Dietz HP, Dombrowski S, Doser M, Dünnweber W, Engelhardt D, Englert M, Faessler MA, Felix C, Folger G, Hackmann R, Haddock RP, Heinsius FH, Hessey NP, Hidas P, Illinger P, Jamnik D, Jávorfi Z, Kalinowsky H, Kämmle B, Kiel T, Kisiel J, Klempt E, Kobel M, Koch H, Kolo C, Königsmann K, Kunze M, Landua R, Lüdemann J, Matthaey H, Merkel M, Merlo JP, Meyer CA, Meyer-Berkhout U, Montanet L, Noble A, Ould-Saada F, Peters K, Pinter G, Ravndal S, Sanjari AH, Schäfer E, Schmid B, Schmidt P, Spanier S, Straßburger C, Strohbusch U, Suffert M, Urner D, Völcker C, Walter F, Walther D, Wiedner U, Winter N, Zoll J, Zupančič Č. Antiproton-proton annihilation at rest into two-body final states. ACTA ACUST UNITED AC 1993. [DOI: 10.1007/bf01560336] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Partridge J, King J, Krska J, Rockabrand D, Blum P. Cloning, heterologous expression, and characterization of the Erysipelothrix rhusiopathiae DnaK protein. Infect Immun 1993; 61:411-7. [PMID: 8423071 PMCID: PMC302744 DOI: 10.1128/iai.61.2.411-417.1993] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
The dnaK (hsp70) gene from the facultative intracellular pathogen Erysipelothrix rhusiopathiae was cloned by heterologous DNA hybridization of a genomic library using the Escherichia coli dnaK gene as a probe. A 3.2-kb fragment which encoded an 1,800-bp open reading frame was recovered. The deduced amino acid sequence of this open reading frame shares 56% identity with the E. coli DnaK protein. Expression of the encoded protein in E. coli by using the phage T7 promoter/polymerase system resulted in accumulation of a unique 65-kDa protein. Western blot (immunoblot) analysis of extracts from a recombinant E. coli strain using anti-E. coli DnaK polyclonal antibodies confirmed that the cloned gene encodes a DnaK homolog. The recombinant E. rhusiopathiae DnaK protein was purified to 80% homogeneity by ATP affinity chromatography. The purified material hydrolyzed ATP with a specific activity of 100 nmol min-1 mg of protein-1. Analysis of total protein extracts from E. rhusiopathiae indicates that DnaK is a highly expressed protein in this organism.
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Lutz RA, Tomasz G, Lüem S, Blum P, Pliska V. Vasopressin receptors in adrenal cortex of sheep: does autoradiography indicate an irreversible binding of the ligand? JOURNAL OF RECEPTOR RESEARCH 1993; 13:283-93. [PMID: 8450494 DOI: 10.3109/10799899309073660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Tritiated arginine vasopressin ([3H]-AVP) labelled specific loci of murine renal medulla and ovine adrenal cortex in thin sections of an autoradiographic experiment. The label was fully displaced by 2 x 10(-6) M cold ligand in the case of renal, but not of adrenal sections. 10 and 100 microM AVP, however, partially displaced the radioactivity also from labelled adrenal sections. At room temperature, the half maximal blackening of the film occurred at a concentration of 26 +/- 0.9 microM. In binding experiments employing AVP and adrenocortical cell membranes, the model assuming two saturable binding sites yielded a significantly better fit than the one-site model. The equilibrium dissociation constants of ice-cold membrane preparations were 8.67 nmol/l for the high affinity site and 3.16 mumol/l for the low affinity binding site. It is concluded that the low affinity binding is governed by laws of chemical equilibrium, rather than by surface adsorption or similar "nonspecific" phenomena. When such low affinity sites are present in a tissue, higher concentrations of cold ligand ought to be used before a nondisplaceable binding is ascribed as "non-specific" or "irreversible".
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Blum P, Ory J, Bauernfeind J, Krska J. Physiological consequences of DnaK and DnaJ overproduction in Escherichia coli. J Bacteriol 1992; 174:7436-44. [PMID: 1429465 PMCID: PMC207440 DOI: 10.1128/jb.174.22.7436-7444.1992] [Citation(s) in RCA: 81] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
The physiological consequences of molecular chaperone overproduction in Escherichia coli are presented. Constitutive overproduction of DnaK from a multicopy plasmid containing large chromosomal fragments spanning the dnaK region resulted in plasmid instability. Co-overproduction of DnaJ with DnaK stabilized plasmid levels. To examine the effects of altered levels of DnaK and DnaJ in a more specific manner, an inducible expression system for dnaK and dnaJ was constructed and characterized. Differential rates of DnaK synthesis were determined by quantitative Western blot (immunoblot) analysis. Moderate levels of DnaK overproduction resulted in a defect in cell septation and formation of cell filaments, but co-overproduction of DnaJ overcame this effect. Further increases in the level of DnaK terminated culture growth despite increased levels of DnaJ. DnaK overproduction was found to be bacteriocidal, and this effect was also partially suppressed by DnaJ. The bacteriocidal effect was apparent only with cultures which were allowed to enter stationary phase, indicating that DnaK toxicity is growth phase dependent.
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Teller R, Blum P, Kostiner E, Hriljac J. Determination of the structure of (VO)3(PO4)2 · 9H2O by powder X-ray diffraction analysis. J SOLID STATE CHEM 1992. [DOI: 10.1016/0022-4596(92)90003-e] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Blum P, Velligan M, Lin N, Matin A. DnaK-Mediated Alterations in Human Growth Hormone Protein Inclusion Bodies. Nat Biotechnol 1992; 10:301-4. [PMID: 1369475 DOI: 10.1038/nbt0392-301] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Protein overproduction in microbes frequently results in protein misfolding and aggregation though the molecular basis for this process is unclear. The HSP70 chaperonin, DnaK, was identified as an important factor controlling heterologous protein aggregation in Escherichia coli. Co-overproduction of DnaK significantly reduced human growth hormone (HGH) protein inclusion body formation and the extent of HGH aggregation.
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Abstract
Stiff-person syndrome (SPS) is characterized by progressive, usually symmetric rigidity of the axial muscles with superimposed painful spasms precipitated by tactile stimuli, passive stretch, volitional movement of affected or unaffected muscles, startling noises, and emotional stimuli. Electromyography demonstrates continuous normal motor unit potentials in the affected muscles. Both the rigidity and the spasms are relieved by sleep, general anesthesia, myoneural blockade, peripheral nerve blockade, and partially by diazepam. Evidence for an autoimmune etiology of SPS includes its association with other autoimmune diseases and autoantibodies and the presence of antibodies against glutamic acid decarboxylase (GAD) in the cerebrospinal fluid (CSF) of many affected patients. We describe two patients with this syndrome who had GAD antibodies in both CSF and serum. Partial relief of the symptoms in these patients by corticosteroid therapy provides additional evidence of an autoimmune etiology of SPS and of the role of immunotherapy in its treatment.
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