51
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Wiśliński M, Popielarz M. Occurrence of prochymosin variants in the abomasum of bovine foetuses and calves. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE A 1994; 41:171-9. [PMID: 7941833 DOI: 10.1111/j.1439-0442.1994.tb00083.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Prochymosin variants were analysed in single abomasa from 67 foetuses (3-9 months of gestation) and 33 calves (about 6 weeks old) of Black-and-White cattle collected in a slaughter house. The method of agarose gel electrophoresis followed by detection of proteolytic activity was used. Three distinct prochymosins A, B and C that occurred singly or in pairs (with equal proteolytic activities of both components) were found. Chymosin A, B and C obtained after conversion of corresponding prochymosins, demonstrated similar electrophoretical mobilities like the three chymosin fractions contained in commercial rennin (Sigma, USA). Our chymosin B showed identical mobility as the amidated form of recombined chymosin B contained in Chymogen (Chr. Hansen's Lab., Denmark A/S). Prochymosin A, B and C in the examined animals were precursors of corresponding chymosins and were controlled by three separate codominant alleles. The following prochymosin phenotypes were found: AA (30), AB (32), AC (4), BB (29), BC (4) and CC (1). Chi-square analysis demonstrated significant differences between the observed and expected numbers of phenotypes. The gene frequencies of prochymosin A, B and C were 0.48, 0.47 and 0.05, respectively.
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Affiliation(s)
- M Wiśliński
- Department of Animal Physiology, Faculty of Veterinary Medicine, Agricultural University, Lublin, Poland
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52
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Tsuchiya K, Gomi K, Kitamoto K, Kumagai C, Tamura G. Secretion of calf chymosin from the filamentous fungus Aspergillus oryzae. Appl Microbiol Biotechnol 1993; 40:327-32. [PMID: 7764387 DOI: 10.1007/bf00170388] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Active calf chymosin was secreted from Aspergillus oryzae transformants when the chymosin cDNA was expressed under the control of glucoamylase gene (glaA) promoter. Secreted prochymosin was autocatalytically activated to the chymosin (0.07-0.16 mg/l). Western blot analysis showed that a secreted protein immunoreactive with an anti-chymosin antibody was of similar size to authentic chymosin. Northern blot analysis revealed that mRNA of the chymosin cDNA was expressed at as high level as that of the glaA gene. The size and the level of the transcript were different among transformants, due to the integration position of the plasmid on the chromosome.
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Affiliation(s)
- K Tsuchiya
- Research Institute of Brewing Resources Co. Ltd., Tokyo, Japan
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53
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Teuber M. Genetic engineering techniques in food microbiology and enzymology. FOOD REVIEWS INTERNATIONAL 1993. [DOI: 10.1080/87559129309540968] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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54
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Abstract
Success in the generation of an antibody-based therapeutic requires careful consideration of the binding site, to achieve specificity and high affinity; of the effector, to produce the desired therapeutic effect; of the means of attachment of the effector to the binding site; production of the end product; and the response made by the patient to the administered compound. Each of these areas is receiving attention by antibody-engineering techniques. The number of potentially useful monoclonal antibodies developed over the last 10 years, and currently in clinical trials or preregistration, is now being increased by these engineered newcomers. It will be interesting to see over the next few years how many of these antibodies, and of which kind, emerge as products.
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Affiliation(s)
- J R Adair
- Celltech Research Division, Celltech Ltd, Slough Berks, U.K
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55
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Gellissen G, Melber K, Janowicz ZA, Dahlems UM, Weydemann U, Piontek M, Strasser AW, Hollenberg CP. Heterologous protein production in yeast. Antonie Van Leeuwenhoek 1992; 62:79-93. [PMID: 1444338 DOI: 10.1007/bf00584464] [Citation(s) in RCA: 59] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The exploitation of recombinant DNA technology to engineer expression systems for heterologous proteins represented a major task within the field of biotechnology during the last decade. Yeasts attracted the attention of molecular biologists because of properties most favourable for their use as hosts in heterologous protein production. Yeasts follow the general eukaryotic posttranslational modification pattern of expressed polypeptides, exhibit the ability to secrete heterologous proteins and benefit from an established fermentation technology. Aside from the baker's yeast Saccharomyces cerevisiae, an increasing number of alternative non-Saccharomyces yeast species are used as expression systems in basic research and for an industrial application. In the following review a selection from the different yeast systems is described and compared.
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56
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Bebbington CR, Renner G, Thomson S, King D, Abrams D, Yarranton GT. High-level expression of a recombinant antibody from myeloma cells using a glutamine synthetase gene as an amplifiable selectable marker. Nat Biotechnol 1992; 10:169-75. [PMID: 1369477 DOI: 10.1038/nbt0292-169] [Citation(s) in RCA: 256] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
We report a method for introducing a glutamine synthetase (GS) selectable marker into myeloma cells in which transfectants are selected by growth in a glutamine-free medium. Vector amplification can subsequently be selected using the specific inhibitor of GS, methionine sulphoximine (MSX). Using this system, DNA sequences encoding a chimeric B72.3 IgG4 antibody were expressed from hCMV-MIE promoters in NSO myeloma cells. A cell line was isolated after a single round of selection for vector amplification which contains approximately 4 copies of the vector, secretes 10-15 pg/cell/day cB72.3 antibody during exponential growth and can accumulate 560 mg/l antibody in a fed-batch air-lift fermentation system. Productivity is stable in the absence of MSX selection.
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57
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Law BA, Mulholland F. 10 The Influence of Biotechnological Developments on Cheese Manufacture. Biotechnol Genet Eng Rev 1991. [DOI: 10.1080/02648725.1991.10750007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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58
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WYNNE M, YADA R. ISOLATION OF MUCOR MIEHEI AND M. PUSILLUS ASPARTIC PROTEINASES FROM PARTIALLY PURIFIED SOURCES USING PREPARATIVE ISOELECTRIC FOCUSING. J Food Biochem 1991. [DOI: 10.1111/j.1745-4514.1991.tb00420.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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59
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Herber WK, Bailey FJ, Carty CE, Heimbach JC, Maigetter RZ. Production of cytotoxic proteins in Escherichia coli: a fermentation process for producing enzymatically active HIV-1 protease. Appl Microbiol Biotechnol 1991; 36:149-52. [PMID: 1368104 DOI: 10.1007/bf00164410] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Two fermentation processes for the tryptophan-regulated expression of active HIV protease (HIV-1 prt) in Escherichia coli are described. Since overexpression of HIV-1 prt results in cell death, stringent control of product expression was necessary to attain high enzyme levels. Such control was achieved by separation of growth and production phases in a two-step process or by implementation of nutrient feed in a one-step process. When the two-stage process was used, soluble product was detectable only when induction occurred at low culture density (A550 less than 3.5). Short induction periods of 1-2 h and rapid harvesting were necessary to recover active product. Similar results were obtained when the single-stage process was operated at 37 degrees C; however, cultivation and induction at 28 degrees C resulted in active enzyme formation following induction at increased cell density (A550 = 10).
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Affiliation(s)
- W K Herber
- Department of Cellular and Molecular Biology, Merck, Sharp and Dohme Research Laboratories, West Point, PA 19486
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60
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Kenny B, Haigh R, Holland IB. Analysis of the haemolysin transport process through the secretion from Escherichia coli of PCM, CAT or beta-galactosidase fused to the Hly C-terminal signal domain. Mol Microbiol 1991; 5:2557-68. [PMID: 1791766 DOI: 10.1111/j.1365-2958.1991.tb02102.x] [Citation(s) in RCA: 61] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Secretion of haemolysin (HlyA) is secA independent, but depends upon two accessory membrane proteins, HlyB and HlyD, encoded by the hly determinant. A fourth (cytoplasmic) protein, HlyC, is required to activate HlyA post-translationally, but has no role in export. Deletion studies have previously shown that the HlyA molecule contains a targeting signal close to the C-terminus which specifically directs its secretion to the medium. This targeting signal has been variously located within the terminal 27, 53, 60 or 113 amino acids. In this paper, we have sought to confirm the presence of a C-terminal targeting signal and to analyse the specificity of the Hly transport system through fusion of C-terminal fragments of HlyA to heterologous polypeptides. A C-terminal fragment (23 kDa) of HlyA, when fused at the C-terminus, efficiently promoted the secretion of the eukaryotic protein prochymosin (PCM) to the medium via HlyB and HlyD. This result is in contrast to previous findings that prochymosin, preceded by the alkaline phosphatase signal sequence, cannot be translocated across the Escherichia coli inner membrane. The HlyA targeting domain was also used to secrete to the medium varying portions of chloramphenicol acetyltransferase (CAT) and 98 per cent of the beta-galactosidase (LacZ) molecule (both E. coli cytoplasmic proteins). In the case of the PCM and CAT fusions the efficiency of secretion was reduced as the proportion of the PCM and CAT molecule increased. This result is consistent with inhibition of secretion through the irreversible folding of the larger passenger protein fragments, or the occlusion of the HlyA targeting signal by upstream sequences. Analysis of the nature of the C-terminal domain promoting secretion of prochymosin, demonstrated that shortening the signal domain from 218 to 113 amino acids significantly reduced the efficiency of secretion. This result may also reflect the importance of maintaining an independently folded signal motif well separated from a passenger domain.
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Affiliation(s)
- B Kenny
- Department of Genetics, University of Leicester, Leicester, UK
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61
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Affiliation(s)
- E L Flamm
- Office of Biotechnology, U.S. Food and Drug Administration, Rockville, MD 20857
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62
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Ward M, Kodama KH. Introduction to fungal proteinases and expression in fungal systems. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 1991; 306:149-60. [PMID: 1812703 DOI: 10.1007/978-1-4684-6012-4_20] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Affiliation(s)
- M Ward
- Genencor International, South San Francisco, California 94080
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63
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Affiliation(s)
- A Kimura
- Kyoto University, Research Institute for Food Science, Japan
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64
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Sheikh A, Freedman RB. Translation of preprochymosin in vitro. Evidence for folding of prochymosin to the native conformation. Biochem J 1990; 272:659-64. [PMID: 2268293 PMCID: PMC1149759 DOI: 10.1042/bj2720659] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
1. The cDNA coding for preprochymosin has been sub-cloned into the transcription/translation vector pGEM-3Z, the T7 promoter used to transcribe the gene and the product expressed in an 'in vitro' cell-free system comprising rabbit reticulocyte lysate and dog pancreatic microsomes. 2. Translations in various conditions, and analyses of the translation product in reducing and non-reducing conditions, indicate that oxidizing translation conditions and the cleavage of the N-terminal 'pre-' sequence are essential for generation of a disulphide-bonded translation product. 3. The disulphide-bonded translation product was resistant to proteinases, as expected for a translation product segregated within microsomal vesicles; in the presence of detergent to solubilize the membranes, the product was not readily susceptible to proteolysis, and was converted to a proteinase-resistant core fragment. 4. Segregated prochymosin, synthesized in reducing conditions, was completely degraded by proteinases under similar conditions. 5. Proteinase treatment of purified recombinant prochymosin gave rise to a proteinase-resistant fragment of similar Mr, suggesting that the disulphide-bonded product of translation in vitro was correctly folded. 6. The translocated, disulphide-bonded and folded prochymosin could be converted into pseudochymosin at pH 2.0, and addition of chymosin to the activation mixture resulted in increased pseudochymosin production.
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Affiliation(s)
- A Sheikh
- Biological Laboratory, University of Kent, Canterbury, U.K
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65
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Affiliation(s)
- T Beppu
- Department of Agricultural Chemistry, University of Tokyo, Japan
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66
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Sugrue R, Marston FA, Lowe PA, Freedman RB. Denaturation studies on natural and recombinant bovine prochymosin (prorennin). Biochem J 1990; 271:541-7. [PMID: 2241930 PMCID: PMC1149589 DOI: 10.1042/bj2710541] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
1. Prochymosin in solution in the presence of 8 M-urea is fully unfolded, as indicated by its fluorescence spectrum, fluorescence quenching behaviour and far-u.v.c.d. spectrum. 2. Equilibrium studies on the unfolding of prochymosin and pepsinogen by urea were carried out at pH 7.5 and pH 9.0. The results indicate that the stabilization energies of the two proteins are identical at pH 7.5, but that at pH 9.0 pepsinogen is significantly less stable than prochymosin. 3. Kinetic studies on the unfolding of prochymosin and pepsinogen indicate that the processes can be described by a single first-order rate constant, and that at any given value of denaturant concentration and pH the rate of unfolding of prochymosin is significantly greater than that of pepsinogen. 4. Unfolding of prochymosin by concentrated urea is not fully reversible, unlike that of pepsinogen. Kinetic analysis of the refolding of the proteins suggests the presence of a slow process following unfolding in urea; for pepsinogen this process leads to a slowly refolding form, whereas for prochymosin the slow process in urea leads to a form that cannot refold on dilution of the denaturant. 5. The results provide a rationale for an empirical process for recovery of recombinant prochymosin after solubilization of inclusion bodies in concentrated urea. 6. In all respects studied here, natural and recombinant bovine prochymosin were indistinguishable, indicating that the refolding protocol yields a recombinant product identical with natural prochymosin.
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Affiliation(s)
- R Sugrue
- Biological Laboratory, University of Kent, Canterbury, U.K
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67
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Thomas CD, Balson DF, Shaw WV. In vitro studies of the initiation of staphylococcal plasmid replication. Specificity of RepD for its origin (oriD) and characterization of the Rep-ori tyrosyl ester intermediate. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39392-5] [Citation(s) in RCA: 67] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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68
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van den Berg JA, van der Laken KJ, van Ooyen AJ, Renniers TC, Rietveld K, Schaap A, Brake AJ, Bishop RJ, Schultz K, Moyer D. Kluyveromyces as a Host for Heterologous Gene Expression: Expression and Secretion of Prochymosin. Nat Biotechnol 1990; 8:135-9. [PMID: 1366557 DOI: 10.1038/nbt0290-135] [Citation(s) in RCA: 107] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
We have developed the yeast Kluyveromyces lactis as a host organism for the production of the milk-clotting enzyme chymosin. In contrast to Saccharomyces cerevisiae, we found that this yeast is capable of the synthesis and secretion of fully active prochymosin. Various signal sequences could be used to efficiently direct the secretion of prochymosin in Kluyveromyces, but not in S. cerevisiae. We conclude that the efficient synthetic and secretory capacity of this heterologous protein is a property of the yeast Kluyveromyces. These results have led to the development of a large scale production process for chymosin.
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Affiliation(s)
- J A van den Berg
- Royal Gist-brocades, Research and Development, Ma Delft, The Netherlands
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69
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Andersson H, Andrén A, Björck L. An Enzyme-Linked Immunosorbent Assay for Detection of Chymosin in Dairy Products. J Dairy Sci 1989. [DOI: 10.3168/jds.s0022-0302(89)79470-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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70
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Stephens PE, Cockett MI. The construction of a highly efficient and versatile set of mammalian expression vectors. Nucleic Acids Res 1989; 17:7110. [PMID: 2780323 PMCID: PMC318444 DOI: 10.1093/nar/17.17.7110] [Citation(s) in RCA: 67] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
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71
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Harkki A, Uusitalo J, Bailey M, Penttilä M, Knowles JKC. A Novel Fungal Expression System: Secretion of Active Calf Chymosin from the Filamentous Fungus Trichoderma Reesei. Nat Biotechnol 1989. [DOI: 10.1038/nbt0689-596] [Citation(s) in RCA: 77] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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72
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Klessen C, Schmidt KH, Gumpert J, Grosse HH, Malke H. Complete secretion of activable bovine prochymosin by genetically engineered L forms of Proteus mirabilis. Appl Environ Microbiol 1989; 55:1009-15. [PMID: 2499253 PMCID: PMC184238 DOI: 10.1128/aem.55.4.1009-1015.1989] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
To circumvent problems encountered in the synthesis of active chymosin in a number of bacteria and fungi, a recombinant DNA L-form expression system that directed the complete secretion of fully activable prochymosin into the extracellular culture medium was developed. The expression plasmid constructions involved the in-frame fusion of prochymosin cDNA minus codons 1 to 4 to streptococcal pyrogenic exotoxin type A gene (speA') sequences, including the speA promoter, ribosomal binding site, and signal sequence and five codons of mature SpeA. Secretion of fusion prochymosin enzymatically and immunologically indistinguishable from bovine prochymosin was achieved after transformation of two stable protoplast type L-form strains derived from Proteus mirabilis. The secreted proenzyme was converted by autocatalytic processing to chymosin showing milk-clotting activity. In controlled laboratory fermentation processes, a maximum specific rate of activable prochymosin synthesis of 0.57 x 10(-3)/h was determined from the time courses of biomass dry weight and product formation. Yields as high as 40 +/- 10 micrograms/ml were obtained in the cell-free culture fluid of strain L99 carrying a naturally altered expression plasmid of increased segregational stability. The expression-secretion system described may be generally useful for production of recombinant mammalian proteins synthesized intracellularly as aberrantly folded insoluble aggregates.
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Affiliation(s)
- C Klessen
- Central Institute of Microbiology and Experimental Therapy, Academy of Sciences of the German Democratic Republic, Jena
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73
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Abstract
Bovine prochymosin produced in Escherichia coli has been used as a model system to investigate factors which may cause a recombinant protein to accumulate as insoluble inclusion bodies. A series of plasmids was constructed to investigate the effect of deletions within the prochymosin-coding sequence on protein inclusion body formation. The results demonstrated that as much as 70% of the prochymosin-coding sequence could be deleted with no significant reduction in the accumulation of insoluble protein. The smallest deletion product identified (11,000 molecular weight) retained only one cysteine, yet this product still accumulated as an insoluble product in E. coli.
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Affiliation(s)
- M T McCaman
- Codon, South San Francisco, California 94080
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74
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Leinwand LA, Sohn R, Frankel SA, Goodwin EB, McNally EM. Bacterial expression of eukaryotic contractile proteins. CELL MOTILITY AND THE CYTOSKELETON 1989; 14:3-11. [PMID: 2684424 DOI: 10.1002/cm.970140104] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- L A Leinwand
- Department of Microbiology, Albert Einstein College of Medicine, Bronx, New York 10461
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75
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Denhardt DT, Colasanti J. A survey of vectors for regulating expression of cloned DNA in E. coli. BIOTECHNOLOGY (READING, MASS.) 1988; 10:179-203. [PMID: 3061514 DOI: 10.1016/b978-0-409-90042-2.50015-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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76
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77
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78
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79
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Temperature optimization ofin vivo expression from theE. coli trp andtrp::lac promoters. Biotechnol Lett 1987. [DOI: 10.1007/bf01024556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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80
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81
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Taylor G, Hoare M, Gray DR, Marston FAO. Size and Density of Protein Inclusion Bodies. Nat Biotechnol 1986. [DOI: 10.1038/nbt0686-553] [Citation(s) in RCA: 63] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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82
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Kang Y, Jimenez-Flores R, Richardson T. Casein genes and genetic engineering of the caseins. BASIC LIFE SCIENCES 1986; 37:95-111. [PMID: 3010937 DOI: 10.1007/978-1-4684-5110-8_9] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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83
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Abstract
Relationships of structure to function of proteins can be studied using chemical modifications of amino-acid side chains and, more recently, recombinant deoxyribonucleic acid techniques to alter primary sequences. A wide array of chemical modifications are available to the food chemist for manipulating the functionality of food proteins. The esterification of side-chain carboxyl groups in proteins to yield polycationic polymers is emphasized in this review as an example of changing the functionality of a protein via chemical derivatization. However, chemical modifications of proteins generally suffer from a lack of control in the extent of derivatization attainable, oftentimes yielding polydisperse products. Recent advances in recombinant deoxyribonucleic acid technology offer the opportunity to relate systematically well-defined alterations in the primary sequence to changes in protein functionality. Using oligonucleotide-directed mutagenesis, one can now use synthetic oligodeoxynucleotides to prepare semisynthetic genes coding for specific changes in the primary sequence of proteins. Incorporation of the altered genes into an appropriate host can lead to the production of the modified protein for structure-function relationship studies. These recombinant deoxyribonucleic acid techniques may eventually provide the means to engineer proteins and enzymes.
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84
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Kingsman SM, Kingsman AJ, Dobson MJ, Mellor J, Roberts NA. Heterologous gene expression in Saccharomyces cerevisiae. Biotechnol Genet Eng Rev 1985; 3:377-416. [PMID: 2418856 DOI: 10.1080/02648725.1985.10647819] [Citation(s) in RCA: 65] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
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85
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Wood CR, Boss MA, Kenten JH, Calvert JE, Roberts NA, Emtage JS. The synthesis and in vivo assembly of functional antibodies in yeast. Nature 1985; 314:446-9. [PMID: 3920532 DOI: 10.1038/314446a0] [Citation(s) in RCA: 93] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The yeast Saccharomyces cerevisiae can synthesize, process and secrete higher eukaryotic proteins. We have investigated the expression of immunoglobulin chains in yeast and demonstrate here the synthesis, processing and secretion of light and heavy chains, the glycosylation of heavy chain, the intracellular localization of these foreign proteins by immunofluorescence, and the detection of functional antibodies in cells co-expressing both chains. This may provide the basis of a microbial fermentation process for the production of monoclonal antibodies. The co-expression of light and heavy chains in Escherichia coli has been reported but functional antibodies were not assembled in vivo. Furthermore, only low-level assembly of these chains was found in vitro.
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86
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Robinson M, Lilley R, Little S, Emtage JS, Yarranton G, Stephens P, Millican A, Eaton M, Humphreys G. Codon usage can affect efficiency of translation of genes in Escherichia coli. Nucleic Acids Res 1984; 12:6663-71. [PMID: 6091031 PMCID: PMC320107 DOI: 10.1093/nar/12.17.6663] [Citation(s) in RCA: 251] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
By inserting synthetic oligonucleotides into a highly expressed gene in E. coli it has been shown that unfavourable codon usage can reduce the maximum translation rate of a protein. However, in the case of the codon used (AGG), a significant effect on translation was only seen at very high transcription rates from a gene containing multiple copies of the unfavourable codon.
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87
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88
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Boss MA, Kenten JH, Wood CR, Emtage JS. Assembly of functional antibodies from immunoglobulin heavy and light chains synthesised in E. coli. Nucleic Acids Res 1984; 12:3791-806. [PMID: 6328437 PMCID: PMC318790 DOI: 10.1093/nar/12.9.3791] [Citation(s) in RCA: 113] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Genes for a murine mu heavy chain and a lambda light chain immunoglobulin have been inserted into bacterial expression plasmids containing the Escherichia coli trp promoter and ribosome binding site. Induction of transcription from the trp promoter results in accumulation of both light and heavy chain polypeptides in appropriate host strains. Both proteins were found as insoluble products. Following extraction and purification of the immunoglobulin containing fractions, antigen binding activity was recovered. The activity demonstrates essentially the same properties as the antibody from the hybridoma from which the genes were cloned.
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89
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Wood CR, Boss MA, Patel TP, Emtage JS. The influence of messenger RNA secondary structure on expression of an immunoglobulin heavy chain in Escherichia coli. Nucleic Acids Res 1984; 12:3937-50. [PMID: 6328446 PMCID: PMC318801 DOI: 10.1093/nar/12.9.3937] [Citation(s) in RCA: 71] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A gene for murine mu heavy chain immunoglobulin has been inserted into a bacterial expression plasmid containing the Escherichia coli trp promoter and ribosome binding site. A low level expression of mu protein was detected. Secondary structure analysis showed the presence of a hairpin loop burying the mu initiation codon. Alteration of secondary structure at this site by oligonucleotide replacement mutagenesis revealed a correlation between mu expression levels and accessibility of the ribosome binding site. Abolition of secondary structure increased mu protein expression over ninety-fold, to a level approximately equal to that of a trpE -mu fusion protein using the native trpE ribosome binding site.
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90
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Kenten J, Helm B, Ishizaka T, Cattini P, Gould H. Properties of a human immunoglobulin epsilon-chain fragment synthesized in Escherichia coli. Proc Natl Acad Sci U S A 1984; 81:2955-9. [PMID: 6328480 PMCID: PMC345199 DOI: 10.1073/pnas.81.10.2955] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
A fragment of the cloned gene for the human myeloma ND epsilon chain, coding for the second, third, and fourth domains of the immunoglobulin, has been coupled to the tryptophan control region of an expression plasmid and subcloned in Escherichia coli. Induction of gene expression results in the synthesis of the expected, antigenically active polypeptide of Mr 40,000, which constitutes 18% of total bacterial protein and yields 55 mg/liter of culture. The immunoglobulin, which is aggregated and packed into large inclusion bodies within the bacterial cell, can be dissolved by denaturing solvents and purified by affinity chromatography using anti-IgE Sepharose. Reduced monomeric chains assemble spontaneously into dimers. On assay to measure the inhibition of binding of 125I-labeled human E myeloma protein to Fc epsilon receptors on cultured human basophils, the cloned gene product exhibited 20% of the activity of the native protein.
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91
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Costanzo M, Pero J. Overproduction and purification of a bacteriophage SPO1-encoded RNA polymerase sigma factor. J Biol Chem 1984. [DOI: 10.1016/s0021-9258(20)82196-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
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