Conditions Resulting in Formation of Properly Assembled Retroviral Capsids within Inclusion Bodies of Escherichia coli

1999 ◽  
Vol 64 (8) ◽  
pp. 1348-1356 ◽  
Author(s):  
Michaela Rumlová-Kliková ◽  
Iva Pichová ◽  
Eric Hunter ◽  
Tomáš Ruml
Keyword(s):  
Escherichia Coli ◽  
Inclusion Bodies ◽  
Amorphous Material ◽  
Bacterial Expression ◽  
Biologically Active ◽  
Capsid Assembly ◽  
Cultivation Medium ◽  
Viral Particles ◽  
Induction Temperature

It has been generally accepted that inclusion bodies (IBs) formed in Escherichia coli consist of non-biologically active aggregated proteins, which are stabilized by non-productive interactions. We show here that bacterial expression of a retroviral capsid polyprotein results in formation of insoluble IBs that contain fully assembled viral particles connected with amorphous material. The efficiency of IBs formation and capsid assembly was not significantly affected by changes in induction temperature, pH of cultivation medium or the level of expression.

scholarly journals The remarkable solubility-enhancing power of Escherichia coli maltose-binding protein

2016 ◽  
Vol 62 (3) ◽  
pp. 377-382
Author(s):  
David S Waugh
Keyword(s):  
Escherichia Coli ◽  
Recombinant Proteins ◽  
Inclusion Bodies ◽  
Binding Protein ◽  
Maltose Binding Protein ◽  
Review Article ◽  
Biologically Active ◽  
Active Protein ◽  
Inactive Form ◽  
Solubility Enhancers

A common problem encountered during the production of recombinant proteins, particularly in bacteria, is their tendency to accumulate in an insoluble and inactive form (i.e., as inclusion bodies). Although sometimes it is possible to convert the aggregated material into native, biologically active protein, this is a time-consuming, costly, and uncertain undertaking. Consequently, a general means of circumventing the formation of inclusion bodies is highly desirable. During the 1990s, it was serendipitously discovered that certain highly soluble proteins have the ability to enhance the solubility of their fusion partners, thereby preventing them from forming insoluble aggregates. In the ensuing years, Escherichia coli maltose-binding protein (MBP) has emerged as one of the most effective solubility enhancers. Moreover, once rendered soluble by fusion to MBP, many proteins are able to fold into their biologically active conformations. This brief review article focuses on our current understanding of what makes MBP such an effective solubility enhancer and how it facilitates the proper folding of its fusion partners.

scholarly journals Expression of recombinant mouse cytosolic carboxypeptidase 6 in Escherichia coli

2020 ◽  
Vol 185 ◽  
pp. 04050
Author(s):  
Ruixue Wang ◽  
Hui-Yuan Wu
Keyword(s):  
Escherichia Coli ◽  
Family Member ◽  
Soluble Fraction ◽  
Bacterial Expression ◽  
Side Chains ◽  
Biophysical Characterization ◽  
Protein Substrates ◽  
Bacterial Lysates ◽  
Induction Temperature

Cytosolic carboxypeptidase 6 (CCP6) is a member of cytosolic carboxypeptidase (CCP) family that catalyze the removal of polyglutamate side chains from protein substrates. Biochemical and biophysical characterization of CCPs requires large quantities of purified proteins. However, no method describing the expression of any mammalian CCP family member from bacteria has been published to our best knowledge. After considerable efforts to improve the solubility of mammalian CCPs expressed in bacteria, including the optimization of induction temperature and by using different receptive cells, we were able to get less expression of mouse CCP6 in soluble fraction of bacterial lysates. We report in this article, the bacterial expression of CCP6 using Arctic Express (DE3) competent cells that co-express the chaperonin system GroEL and GroES from Oleispira antarctica. However, to achieve a large number of soluble target proteins, the expression conditions still need to be further optimized.

Electron Microscopy of a Herpesvirus Isolated from Marek's Disease in Duck and Chicken Embryo Fibroblast Cultures

1968 ◽  
Vol 26 ◽  
pp. 222-223 ◽  
Author(s):  
Keyvan Nazerian
Keyword(s):  
Inclusion Bodies ◽  
Chicken Embryo Fibroblast ◽  
Marek's Disease ◽  
Marek’S Disease ◽  
Duck Embryo Fibroblast ◽  
Multinucleated Cells ◽  
Viral Particles ◽  
Infected Cells ◽  
And Control ◽  
Do So

A herpes-like virus has been isolated from duck embryo fibroblast (DEF) cultures inoculated with blood from Marek's disease (MD) infected birds. Cultures which contained this virus produced MD in susceptible chickens while virus negative cultures and control cultures failed to do so. This and other circumstantial evidence including similarities in properties of the virus and the MD agent implicate this virus in the etiology of MD.Histochemical studies demonstrated the presence of DNA-staining intranuclear inclusion bodies in polykarocytes in infected cultures. Distinct nucleo-plasmic aggregates were also seen in sections of similar multinucleated cells examined with the electron microscope. These aggregates are probably the same as the inclusion bodies seen with the light microscope. Naked viral particles were observed in the nucleus of infected cells within or on the edges of the nucleoplasmic aggregates. These particles measured 95-100mμ, in diameter and rarely escaped into the cytoplasm or nuclear vesicles by budding through the nuclear membrane (Fig. 1). The enveloped particles (Fig. 2) formed in this manner measured 150-170mμ in diameter and always had a densely stained nucleoid. The virus in supernatant fluids consisted of naked capsids with 162 hollow, cylindrical capsomeres (Fig. 3). Enveloped particles were not seen in such preparations.

High Voltage Electron Microscopy of Viral Inclusion Bodies

1980 ◽  
Vol 38 ◽  
pp. 486-487 ◽  
Author(s):  
H.M. Mazzone ◽  
W.F. Engler ◽  
G. Wray ◽  
A. Szirmae ◽  
J. Conroy ◽  
...  
Keyword(s):  
New York ◽  
Environmental Protection Agency ◽  
Inclusion Bodies ◽  
Host Cells ◽  
High Voltage Electron Microscopy ◽  
Voltage Electron ◽  
Viral Particles ◽  
Pest Insects ◽  
Viral Inclusion ◽  
Insect Gut

Viral inclusion bodies isolated from infected pest insects are being evaluated by the U.S. Dept. of Agriculture as biological insecticides against their hosts. Our research on these inclusion bodies constitutes part of an effort to support their approval by the Environmental Protection Agency as insect control agents. The inclusion bodies in this study are polyhedral in shape and contain rod-shaped viral particles. When ingested by pest insects, the inclusion bodies are broken down in the insect gut and release the viral particles which infect and multiply in the nuclei of host cells. These viruses are termed nucleopolyhedrosis viruses (NPV) and are representatives of the baculoviruses (Wildy, P. 1971 IN J.L. Melnick, ed., Monographs in Virology, vol. 5, S.Karger, New York).

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