ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Purification of a pyrogen-free human growth hormone antagonist (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 48 (1995), S. 520-528 
    Details
    ISSN: 0006-3592
    Keywords: human growth hormone ; animal cell culture ; purification ; serum ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Human growth hormone (hGH) is a polypeptide with 191 amino acids and a molecular mass of 22 kilodaltons. With the aid of computer molecular simulation, an hGH analog was created by altering an hGH gene to reflect the change of one amino acid (glycine [G] 120 to arginine [R]) within the third α-helix of the hGH molecule. This hGH analog, named hGHG120R, was found to be an hGH antagonist. It may have important implications in treating human conditions in which hGH levels are abnormally high, as found in type I diabetics. Several hundred milligrams of purified hGHG120R were needed to determine the biological activity of the antagonist in animal models. A multistep downstream process was developed to purify hGHG120R from cultured mouse L cells transfected with the hGHG120R gene. The process consisted of cell clarification, salt precipitation, membrane ultrafiltration, reversed phase high performance liquid chromatography, phase separation, and lyophiliation. This work discusses the rationale for the design of the process and experimental results on the purification of hGHG120R using the process. © 1995 John Wiley & Sons, Inc.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260480515
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Production of essential L-branched-chain amino acids in bioreactors containing artificial cells immobilized multienzyme systems and dextran-NAD+ (1990)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 36 (1990), S. 263-269 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: We prepared artificial cells each containing leucine dehydrogenase (EC 1.4.1.9), urease (EC 3.5.1.5), soluble dextran-NAD+, and one of the following coenzyme regenerating dehydrogenases: glucose dehydrogenase (EC 1.1.1.47); yeast alcohol dehydrogenase (EC 1.1.1.1); malate dehydrogenase (EC 1.1.1.37); or lactate dehydrogenase (EC 1.1.1.27). Artificial cells were packed in small columns. L-Leucine, L-valine, and L-isoleucine were continuously produced with simultaneous dextran-NADH regeneration. The maximum production ratios depended on the coenzyme regenerating systems used: 83-93% for D-glucose and glucose dehydrogenase system; 90% for ethanol and yeast alcohol dehydrogenase system; 45-55% for L-malate and malate dehydrogenase system; and 64-78% for L-lactate and lactate dehydrogenase system. Kinetic experiments were also carried out. The apparent Km values are as follows: 0.33 mM for α-ketoisocaproate (KIC); 0.51 mM for α-ketoisovalerate (KIV); 0.58 mM for DL-α-keto-β-methyl-n-valerate (KMV); 3.52 mM for urea; 27.82 mM for D-glucose; 3.89 mM for ethanol; 3.02 mM for L-malate; and 16.67 mM for L-lactate. Kinetic analysis showed that KIC, KIV, and KMV were all competitive inhibitors in the reactions catalyzed by leucine dehydrogenase. Their inhibitor constants were the corresponding Km values.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260360308
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Foreign gene expression (β-galactosidase) during the cell cycle phases in recombinant CHO cells (1993)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 42 (1993), S. 1113-1123 
    Details
    ISSN: 0006-3592
    Keywords: cell cycle analysis ; β-galactosidase ; gene expression, foreign ; dihydrofolate reductase ; recombinant CHO cells ; cytomegalovirus promoter ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Recombinant mammalian cultures for heterologous gene expression typically involve cells traversing the cell cycle. Studies were conducted to characterize rates of accumulation of intracellular foreign protein in single cells during the cell cycle of Chinese hamster ovary (CHO) cells transfected with an expression vector containing the gene for dihydrofolate reductase (dhfr) and the lacZ gene for bacterial β-galactosidase (a nonsecreated protein). The lacZ gene was under the control of the constitutive cytomegalovirus promoter. These normally attachment-grown cells were adapted to suspension culture in 10-7 M methotrexate, and a dual-laser flow cytometer was used to simultaneously determine the DNA and foreign protein (β-galactosidase) content of single living cells. Expression of β-galactosidase as a function of cell cycle phase was evaluated for cells in the exponential growth phase, early plateau phase, and inhibited traverse of the cell cycle during exponential growth. The results showed that the β-galactosidase production rate is higher in the S phase than that in the G1 or G2/M phases. Also, when cell cycle progression was stopped at the S phase by addition of aphidicolin, β-galactosidase content in single cells was higher than that in exponential phase or plateau phase cells and increased with increasing culture time. Although the cells did not continue to divide after aphidicolin addition, the production of β-galactosidase per unit volume of culture was very similar to that in normal exponential growth. © 1993 John Wiley & Sons, Inc.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260420914
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Conversion of α-ketoglutarate into L-glutamic acid with urea as ammonium source using multienzyme systems and dextran-NAD+ immobilized by microencapsulation within artificial cells in a bioreactor (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 32 (1988), S. 363-368 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Urea could be effectively converted into L-glutamic acid with semipermeable nylon-polyethylenimine artificial cells containing L-glutamic dehydrogenase (EC 1.4.1. 3), yeast alcohol dehydrogenase (EC 1.1.1.1), urease (EC 3.5.1. 5) and soluble dextran-NAD+. For batch conversion, the artificial cell suspension to total reaction volume ratios ranged from 1 in 5 to 1 in 60. From 22.6 to 53.4 μmol of L-glutamic acid could be produced by 0.4 mL artificial cell suspension within 2 h. The corresponding conversion ratios were 56.5-11. 1%. The L-glutamic dehydrogenase multienzyme system showed a good storage stability: 66.0% of the original activity was retained after 1 month of storage at 4°C. A small bioreactor was prepared to contain 4.0 mL artificial cells. At a flow rate of SV = 1.5 h-1, the maximum conversion rate was 49.6 μmol L-glutamic acid/p h. Thirty-eight percent of the maximum activity was retained when continuously used for four days at 22°C. A kinetic analysis for the L-glutamic dehydrogenase multienzyme system was studied. The Michaelis constants are as follows: α-ketoglutarate is 0.838 mM; urea is 1.90 mM; dextran- NAD+ is 0.345 mM; and ethanol is 5.31 mM.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260320315
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Some considerations for optimization of desorption chromatography (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 37 (1991), S. 65-70 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effect of isotherm parameters of a displacer on the efficiency of desorption Chromatography has been investigated numerically. A general nonlinear multicomponent rate equation model with Langmuir isotherm was used in this study. It was found that the best displacer in this kind of operation is usually not the one that is more strongly adsorbed than the adsorbates when the operation is to displace and concentrate the adsorbates from a saturated or partially saturated column and to minimize the amount of displacer used. The desorption Chromatography is different from the classical displacement development in both operational purpose and the requirement for the displacer. The desorption Chromatography in industrial practice was also analyzed and discussed for the case in which the displacer is introduced in either the same or the reverse flow direction after an incomplete frontal adsorption operation.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260370110
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Effects of p-cresol and chlorophenols on pentachlorophenol biodegradation (1995)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 47 (1995), S. 470-475 
    Details
    ISSN: 0006-3592
    Keywords: chlorophenol ; cresol ; cell growth ; flavobacterium species ; cell death ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The effects of three aromatic compounds, p-cresol, 2,4-dichlorophenol (DCP), and 2,4,6-trichlorophenol (TCP), on cell growth and pentachlorophenol (PCP) degradation bya Flavobacterium species were investigated. While p-cresol was not degraded by this bacterium, DCP and TCP were simultaneously degraded with PCP. Both DCP and TCP lowered cell growth and PCP degradation rate. Cell growth was modeled by cell death, because p-cresol, DCP, and TCP were toxic to the organism. A new model was used to predict cell death rate in a mixture of two toxic compounds from the cell death kinetics for each individual compound. PCP degradation rates were modeled by conventional inhibition models, but only over a small concentration range for the secondary toxic compound. However, a new empirical model described PCP degradation over a wider concentration range of the secondary toxic compound. © 1995 John Wiley & Sons Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260470408
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Microcarrier culture of bowes melanoma cells in serum-free medium with Human plasma fraction IV-4+ V (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 38 (1991), S. 247-253 
    Details
    ISSN: 0006-3592
    Keywords: serum-free medium ; fractionated human plasma ; plasminogen activator ; growth stimulatory activities ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Bowes melanoma cells were cultivated successfully in a serum-free medium which was constructed by the concept of maximum retention of proteins from fractionated human plasma having growth stimulatory activities. The cells could be cultivated in the serum-free medium without any adaptation period. The major serum-free component of the medium was the fraction IV-4 + V of the Cohn fractionation process of human plasma. Approximately six times increase of tissue-type plasminogen activator (t-PA) activity as compared with that in serum-free medium even though the cell growth was much slower. In addition, the growth stimulatory activities of thrombin and fibronectin were investigated during the cultivation of Bowes melanoma cells in this serum-free medium. These proteins contributed significantly to the enhanced growth of cells by reducing doubling time to 25 and 35 h as compared with 55 h in the serum-free medium without them. Especially, fibronectin supported cells to propagate near to the maximum cell density achieved in the medium with 10% FBS.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260380306
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Influence of Primatone RL supplementation on sialylation of recombinant human interferon-γ produced by Chinese hamster ovary cell culture using serum-free media (1997)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 56 (1997), S. 353-360 
    Details
    ISSN: 0006-3592
    Keywords: Primatone RL ; sialylation ; interferon-γ ; serum substitutes ; cell ; CHO cell culture ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Although serum-free media have been widely used in mammalian cell culture for therapeutic protein production, the effects of serum-substitutes on product quality have not been extensively examined. This study observed an adverse effect of Primatone RL, an animal tissue hydrolysate commonly used as a serum-substitute to promote cell growth, on sialylation of interferon-γ (IFN-γ) derived from Chinese hamster ovary (CHO) cell culture in both batch and fed-batch modes. In batch cultures, decreased sialylation was observed at each of the glycosylation sites (i.e., Asn25 and Asn97) of IFN-γ with the use of elevated concentrations of the peptone. Although poorest sialylation was obtained with the use of a growth-inhibiting concentration of Primatone RL, diminished sialylation was observed at the optimal peptone concentration for cell growth and product yield. Since incubation of the product in Primatone RL-supplemented acellular medium did not result in decreased sialylation, the negative effect of Primatone RL could not be attributed to extracellular desialylation of IFN-γ by components of the peptone. In the fed-batch mode, a culture utilizing a serum-free feeding medium supplemented with Primatone RL demonstrated poorer sialylation than a similar culture not fed the peptone. The results of both the batch and fed-batch experiments indicate that the adverse effect of the peptone was not due solely to ammonia accumulation. © 1997 John Wiley & Sons, Inc. Biotechnol Bioeng 56: 353-360, 1997.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 9
    Electronic Resource
    Electronic Resource
    Cell cycle analysis of foreign gene (β-galactosidase) expression in recombinant mouse cells under control of mouse mammary tumor virus promoter (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 50 (1996), S. 229-237 
    Details
    ISSN: 0006-3592
    Keywords: cell cycle analysis ; foreign gene expression ; MMTV promoter control ; recombinant mouse cells ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: The cell cycle dependency of foreign gene expression in recombinant mouse L cells was investigated. Two different recombinant mouse L cell lines having the glucocorticoid receptor-encoding gene and the lacZ reporter gene were used in this study. The lacZ gene expression was controlled by the glucocorticoid-inducible mouse mammary tumor virus (MMTV) promoter in both cell lines. In “M4” cells the gr gene was under the control of another MMTV promoter, but in “R2” cells it was under the control of the constitutive Rous sarcoma virus promoter. These normally attachment-grown cells were adapted to suspension culture, and a dual-laser flow cytometer was used to simultaneously determine the DNA and foreign protein (β-galactosidase) content of single living cells. Expression of β-galactosidase as a function of cell cycle phase was evaluated for cells in exponential growth without any addition of the glucocorticoid inducer, dexamethasone. Cell cycle positions in the S phase were estimated on the basis of DNA content per cell, and position in the G1 phase was estimated on the basis of cell size as measured by pulse-width time of flight. The results showed that β-galactosidase synthesis occurred through all cell cycle phases, but the expression rate in the G1 phase was much lower than that in the S and G2/M phases in both cell lines. On the basis of cell size analysis, β-galactosidase expression in M4 cells (with autoinducible promoter) was found to be higher than that in R2 cells (with inducible promoter) during the G1 phase. © 1996 John Wiley & Sons, Inc.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
  • 10
    Electronic Resource
    Electronic Resource
    Propionic acid production by extractive fermentation. I. Solvent considerations (1998)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 57 (1998), S. 454-461 
    Details
    ISSN: 0006-3592
    Keywords: propionic acid ; extractive fermentation ; solvent ; partition ; acid recovery ; Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Solvent selection for extractive fermentation for propionic acid was conducted with three systems: Alamine 304-1 (trilaurylamine) in 2-octanol, 1-dodecanol, and Witcohol 85 NF (oleyl alcohol). Among them, the solvent containing 2-octanol exhibited the highest partition coefficient in acid extraction, but it was also toxic to propionibacteria. The most solvent-resistant strain among five strains of the microorganism was selected. Solvent toxicity was eliminated via two strategies: entrapment of dissolved toxic solvent in the culture growth medium with vegetable oils such as corn, olive, or soybean oils; or replacement of the toxic 2-octanol with nontoxic Witcohol 85 NF. The complete recovery of acids from the Alamine 304-1/Witcohol 85 NF was also realized with vacuum distillation. ©1998 John Wiley & Sons, Inc. Biotechnol Bioeng 57: 454-461, 1998.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...