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1.
Recombinant human insulin. 总被引:1,自引:0,他引:1
Insulin is a well-characterized peptide that can be produced by recombinant DNA technology for human therapeutic use. A brief overview of insulin production from both traditional mammalian pancreatic extraction and recombinant bacterial and yeast systems is presented, and detection techniques, including electrophoresis, are reviewed. Analytical systems for insulin separation are principally based on reversed-phase chromatography, which resolves the deamidation product(s) (desamido insulin) of insulin, proinsulin, and insulin. Process-scale separation is a multistep process and includes ion exchange, reversed-phase, and size exclusion chromatography. Advantages and/or disadvantages of various separation approaches, as described by the numerous literature references on insulin purification, are presented. 相似文献
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Dugas M Schoch C Schnittger S Kohlmann A Kern W Haferlach T Uberla K 《In silico biology》2002,2(3):383-391
To assess the relevance of molecular markers it is required to combine clinical and genetic information. For reliable assessment of parameters relevant to diagnostics and therapy large patient collectives must be characterized both with respect to phenotype and genotype. Matching of genetic data like gene expression profiles, molecular genetics and cytogenetics with clinical data like follow-up, morphological findings and diagnoses involves integration of complex databases. In the context of a nationwide leukemia research network in Germany we designed an integrated database covering both genetic and clinical data of patients. The system contains follow-up data and relevant laboratory modalities, i. e. cytomorphology, cytogenetics, molecular genetics, FISH, immunophenotyping and gene expression profiling. So far 13,541 cases from 7,746 patients treated by 1,225 physicians are documented. The data structure consists of up to 888 variables per case. From our experience, integration of clinical and genetic information requires significant efforts - including data protection issues -, but is feasible and improves data quality leading to faster and more reliable research results for the benefit of the patients. 相似文献
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We investigated patch assessment by northern bobwhites (Collinusvirginianus) in an experimental arena where the distributionof resources in patches, preharvest information about thesepatches, and spacing of patches varied. We found that preharvestinformation about patch quality and a bimodal distribution ofpatch rewards allowed birds to selectively exploit patches highin resources. In contrast, uniform distribution of patch qualitiesand lack of preharvest information caused birds to forage nonselectivelyamong patches. Birds distinguished among patches of differentquality when these patches were spaced 13 m apart, but failedto react to patch quality differences when patches were 0 or3 m apart We also found a strong effect of the level of patchdepletion on foraging decisions: as resources in die arena becamescarce, birds increasingly foraged selectively in die most profitablepatches. Foraging decisions of bobwhites are biased by die waythey experience and memorize a spatially and temporally variableenvironment. The relative cost of this cognitive bias (i.e.,lost opportunity) is nonlinearty related to die mean resourcedensity in die environment and to die difference between thismean density and die resource density in die exploited patch.Cognitive bias should be considered when evaluating patch assessmentcapabilities of foragers in complex environments. 相似文献
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Kohlmann Y Pohlmann A Otto A Becher D Cramm R Lütte S Schwartz E Hecker M Friedrich B 《Journal of proteome research》2011,10(6):2767-2776
The soil-dwelling lithoautotrophic bacterium Ralstonia eutropha H16 utilizes hydrogen as the key source of energy during aerobic growth on hydrogen and carbon dioxide. We examined the soluble and membrane protein complements of lithoautotrophically grown cells and compared them to the protein complements of cells grown organoheterotrophically on succinate. (14)N/(15)N-based inverse metabolic labeling in combination with GeLC-MS led to the identification of 1452 proteins, 1174 of which could be quantitated. Far more proteins were found to be more abundant in the lithoautotrophically than in the organoheterotrophically grown cells. In addition to the induction of the key enzymes of hydrogen oxidation and carbon dioxide fixation, we observed several characteristic alterations in the proteome correlated with lithoautotrophic growth. (I) Genes for three terminal oxidases were upregulated. (II) NAD(P) transhydrogenase and enzymes for the accumulation of poly(3-hydroxybutyrate) (PHB) showed increased protein abundance. (III) Lithoautotrophically grown cells were equipped with an enhanced inventory of transport systems. (IV) The expression of cell surface appendages involved in cell movement was markedly increased, while proteins involved in cell adhesion were decreased. Our data show that the hydrogen-based lifestyle of R. eutropha H16 relies on an extensive protein repertoire adapting the organism to the alternative energy and carbon sources. 相似文献
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To identify new components of the protein quality control and degradation pathway of the endoplasmic reticulum (ER), we performed a growth-based genome-wide screen of about 5000 viable deletion mutants of the yeast Saccharomyces cerevisiae. As substrates we used two misfolded ER membrane proteins, CTL* and Sec61-2L, chimeric derivatives of the classical ER degradation substrates CPY* and Sec61-2. Both substrates contain a cytosolic Leu2 protein fusion, and stabilization of these substrates in ER-associated degradation-deficient strains enables a restored growth of the transformed LEU2-deficient deletion mutants. We identified the strain deleted for the ubiquitin chain elongating ligase Hul5 among the mutant strains with a strong growth phenotype. Here we show that Hul5 is necessary for the degradation of two misfolded ER membrane substrates. Although the degradation of their N-terminal parts is Hul5-independent, the breakdown of their C-terminal fragments requires the ubiquitin chain elongating ligase activity of Hul5. In the absence of Hul5, a truncated form of CTL*myc remains to a large extent embedded in the ER membrane. Hul5 activity promotes the interaction of this truncated CTL*myc with the AAA-ATPase Cdc48, which is known to pull proteins out of the ER membrane. This study unravels the stepwise elimination of the ER membrane-localized CTL*myc substrate. First, N-terminal, lumenal CPY* is transferred to the cytoplasm and degraded by the proteasome. Subsequently, the remaining C-terminal membrane-anchored part requires Hul5 for its effective extraction out of the endoplasmic reticulum and proteasomal degradation. 相似文献
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N.A. Klimenko R.M. Marutovsky V.V. Pidlisnyuk L.V. Nevinnaya S.K. Smolin J. Kohlmann K.‐H. Radeke 《Engineering in Life Science》2002,2(10):317-324
An analysis is made of the literature on the mechanism of biosorption‐bioregeneration of organic substances mainly on activated carbon (AC). There have advanced two hypotheses on the biosorption mechanism: the Rodman exoenzymatic hypothesis and the bioregeneration approach of Andrews and Chi Tien. In addition, it was shown that the principal mechanism responsible for the removal of both biodegradable and bioresistant compounds is biological oxidation, but only in combination with adsorption on activated carbon. The authors examine the role of the filter medium in biosorption, factors affecting efficiency of biosorption and bioregeneration of AC and technological aspects of the application of biosorptive processes. 相似文献
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Edward Schwartz Birgit Voigt Daniela Zühlke Anne Pohlmann Oliver Lenz Dirk Albrecht Alexander Schwarze Yvonne Kohlmann Cornelia Krause Michael Hecker Bärbel Friedrich 《Proteomics》2009,9(22):5132-5142
Ralstonia eutropha H16 is an H2‐oxidizing, facultative chemolithoautotroph. Using 2‐DE in conjunction with peptide mass spectrometry we have cataloged the soluble proteins of this bacterium during growth on different substrates: (i) H2 and CO2, (ii) succinate and (iii) glycerol. The first and second conditions represent purely lithoautotrophic and purely organoheterotrophic nutrition, respectively. The third growth regime permits formation of the H2‐oxidizing and CO2‐fixing systems concomitant to utilization of an organic substrate, thus enabling mixotrophic growth. The latter type of nutrition is probably the relevant one with respect to the situation faced by the organism in its natural habitats, i.e. soil and mud. Aside from the hydrogenase and Calvin‐cycle enzymes, the protein inventories of the H2‐CO2‐ and succinate‐grown cells did not reveal major qualitative differences. The protein complement of the glycerol‐grown cells resembled that of the lithoautotrophic cells. Phosphoenolpyruvate (PEP) carboxykinase was present under all three growth conditions, whereas PEP carboxylase was not detectable, supporting earlier findings that PEP carboxykinase is alone responsible for the anaplerotic production of oxaloacetate from PEP. The elevated levels of oxidative stress proteins in the glycerol‐grown cells point to a significant challenge by ROS under these conditions. The results reported here are in agreement with earlier physiological and enzymological studies indicating that R. eutropha H16 has a heterotrophic core metabolism onto which the functions of lithoautotrophy have been grafted. 相似文献
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Liu WM Li R Sun JZ Wang J Tsai J Wen W Kohlmann A Williams PM 《Journal of theoretical biology》2006,243(2):273-278
An ideal expression algorithm should be able to tell truly different expression levels with small false positive errors and be robust to assay changes. We propose two algorithms. PQN is the non-central trimmed mean of perfect match intensities with quantile normalization. DQN is the non-central trimmed mean of differences between perfect match and mismatch intensities with quantile normalization. The quantiles for normalization can be either empirical or theoretical. When array types and/or assay change in a study, the normalization to common quantiles at the probe set level is essential. We compared DQN, PQN, RMA, GCRMA, DCHIP, PLIER and MAS5 for the Affymetrix Latin square data and our data of two sets of experiments using the same bone marrow but different types of microarrays and different assay. We found the computation for AUC of ROC at affycomp.biostat.jhsph.edu can be improved. 相似文献
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James L. Sherwood Claire Corcoran Helen Brown Alan D. Sharpe Milena Musilova Alexander Kohlmann 《PloS one》2016,11(2)