scholarly journals Quality Screening of Incorrectly Folded Soluble Aggregates from Functional Recombinant Proteins

2019 ◽  
Vol 20 (4) ◽  
pp. 907 ◽  
Author(s):  
Soon Kwon ◽  
Ji Yu ◽  
Jihoon Kim ◽  
Hana Oh ◽  
Chan Park ◽  
...  
Keyword(s):  
Recombinant Proteins ◽  
Enhanced Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Host Cells ◽  
Purification Step ◽  
Reporter System ◽  
Functional Quality ◽  
Soluble Aggregates ◽  
Green Fluorescent

Solubility is the prime criterion for determining the quality of recombinant proteins, yet it often fails to represent functional activity due to the involvement of non-functional, misfolded, soluble aggregates, which compromise the quality of recombinant proteins. However, guidelines for the quality assessment of soluble proteins have neither been proposed nor rigorously validated experimentally. Using the aggregation-prone enhanced green-fluorescent protein (EGFP) folding reporter system, we evaluated the folding status of recombinant proteins by employing the commonly used sonication and mild lysis of recombinant host cells. We showed that the differential screening of solubility and folding competence is crucial for improving the quality of recombinant proteins without sacrificing their yield. These results highlight the importance of screening out incorrectly folded soluble aggregates at the initial purification step to ensure the functional quality of recombinant proteins.

scholarly journals The Functional Quality of Soluble Recombinant Polypeptides Produced in Escherichia coli Is Defined by a Wide Conformational Spectrum

2008 ◽  
Vol 74 (23) ◽  
pp. 7431-7433 ◽  
Author(s):  
Mónica Martínez-Alonso ◽  
Nuria González-Montalbán ◽  
Elena García-Fruitós ◽  
Antonio Villaverde
Keyword(s):  
Escherichia Coli ◽  
Green Fluorescent Protein ◽  
Recombinant Proteins ◽  
Fluorescent Protein ◽  
Native Structure ◽  
Functional Quality ◽  
Soluble Aggregates ◽  
Recombinant Polypeptides ◽  
Green Fluorescent

ABSTRACT We have observed that a soluble recombinant green fluorescent protein produced in Escherichia coli occurs in a wide conformational spectrum. This results in differently fluorescent protein fractions in which morphologically diverse soluble aggregates abound. Therefore, the functional quality of soluble versions of aggregation-prone recombinant proteins is defined statistically rather than by the prevalence of a canonical native structure.

scholarly journals A functional chimaeric S-layer-enhanced green fluorescent protein to follow the uptake of S-layer-coated liposomes into eukaryotic cells

2004 ◽  
Vol 379 (2) ◽  
pp. 441-448 ◽  
Author(s):  
Nicola ILK ◽  
Seta KÜPCÜ ◽  
Gerald MONCAYO ◽  
Sigrid KLIMT ◽  
Rupert C. ECKER ◽  
...  
Keyword(s):  
Green Fluorescent Protein ◽  
Fusion Protein ◽  
Hela Cells ◽  
Enhanced Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Laser Scanning Microscopy ◽  
Host Cells ◽  
Confocal Laser ◽  
Green Fluorescent ◽  
Egfp Fluorescence

The chimaeric gene encoding a C-terminally truncated form of the S-layer protein SbpA of Bacillus sphaericus CCM 2177 and the EGFP (enhanced green fluorescent protein) was ligated into plasmid pET28a and cloned and expressed in Escherichia coli. Just 1 h after induction of expression an intense EGFP fluorescence was detected in the cytoplasm of the host cells. Expression at 28 °C instead of 37 °C resulted in clearly increased fluorescence intensity, indicating that the folding process of the EGFP moiety was temperature sensitive. To maintain the EGFP fluorescence, isolation of the fusion protein from the host cells had to be performed in the presence of reducing agents. SDS/PAGE analysis, immunoblotting and N-terminal sequencing of the isolated and purified fusion protein confirmed the presence of both the S-layer protein and the EGFP moiety. The fusion protein had maintained the ability to self-assemble in suspension and to recrystallize on peptidoglycan-containing sacculi or on positively charged liposomes, as well as to fluoresce. Comparison of fluorescence excitation and emission spectra of recombinant EGFP and rSbpA31-1068/EGFP revealed identical maxima at 488 and 507 nm respectively. The uptake of liposomes coated with a fluorescent monomolecular protein lattice of rSbpA31-1068/EGFP into HeLa cells was studied by confocal laser-scanning microscopy. The major part of the liposomes was internalized within 2 h of incubation and entered the HeLa cells by endocytosis.

A versatile and economical method for the release of recombinant proteins from Escherichia coli by 1-propanol cell disruption

RSC Advances ◽  
2016 ◽  
Vol 6 (67) ◽  
pp. 62291-62297 ◽  
Author(s):  
Sewn Cen Lo ◽  
Ramakrishnan Nagasundara Ramanan ◽  
Beng Ti Tey ◽  
Weng Siang Tan ◽  
Pau Loke Show ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Green Fluorescent Protein ◽  
Recombinant Proteins ◽  
Enhanced Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Cell Disruption ◽  
Economical Method ◽  
P Release ◽  
Green Fluorescent

Release of enhanced green fluorescent protein from Escherichia coli by 1-propanol cell disruption.

scholarly journals Enhanced Green Fluorescent Protein (GFP) fluorescence after polyelectrolyte caging

2006 ◽  
Vol 14 (21) ◽  
pp. 9815 ◽  
Author(s):  
Alberto Diaspro ◽  
Silke Krol ◽  
Barbara Campanini ◽  
Fabio Cannone ◽  
Giuseppe Chirico
Keyword(s):  
Green Fluorescent Protein ◽  
Enhanced Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Gfp Fluorescence ◽  
Green Fluorescent

scholarly journals Development and Characterization of a cDNA-Launch Recombinant Simian Hemorrhagic Fever Virus Expressing Enhanced Green Fluorescent Protein: ORF 2b’ Is Not Required for In Vitro Virus Replication

Viruses ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 632
Author(s):  
Yingyun Cai ◽  
Shuiqing Yu ◽  
Ying Fang ◽  
Laura Bollinger ◽  
Yanhua Li ◽  
...  
Keyword(s):  
Green Fluorescent Protein ◽  
Cell Lines ◽  
Enhanced Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Infectious Clone ◽  
Hemorrhagic Fever ◽  
Simian Hemorrhagic Fever Virus ◽  
Hemorrhagic Fever Virus ◽  
Green Fluorescent

Simian hemorrhagic fever virus (SHFV) causes acute, lethal disease in macaques. We developed a single-plasmid cDNA-launch infectious clone of SHFV (rSHFV) and modified the clone to rescue an enhanced green fluorescent protein-expressing rSHFV-eGFP that can be used for rapid and quantitative detection of infection. SHFV has a narrow cell tropism in vitro, with only the grivet MA-104 cell line and a few other grivet cell lines being susceptible to virion entry and permissive to infection. Using rSHFV-eGFP, we demonstrate that one cricetid rodent cell line and three ape cell lines also fully support SHFV replication, whereas 55 human cell lines, 11 bat cell lines, and three rodent cells do not. Interestingly, some human and other mammalian cell lines apparently resistant to SHFV infection are permissive after transfection with the rSHFV-eGFP cDNA-launch plasmid. To further demonstrate the investigative potential of the infectious clone system, we introduced stop codons into eight viral open reading frames (ORFs). This approach suggested that at least one ORF, ORF 2b’, is dispensable for SHFV in vitro replication. Our proof-of-principle experiments indicated that rSHFV-eGFP is a useful tool for illuminating the understudied molecular biology of SHFV.

scholarly journals The Reporter System for GPCR Assay with the Fission YeastSchizosaccharomyces pombe

Scientifica ◽  
2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Shintaro Sasuga ◽  
Toshiya Osada
Keyword(s):  
Fluorescent Protein ◽  
Signal To Noise Ratio ◽  
Biological Activities ◽  
Inducible Promoter ◽  
Upstream Region ◽  
Reporter Plasmid ◽  
Reporter System ◽  
High Background ◽  
Downstream Region ◽  
Green Fluorescent

G protein-coupled receptors (GPCRs) are associated with a great variety of biological activities. Yeasts are often utilized as a host for heterologous GPCR assay. We engineered the intense reporter plasmids for fission yeast to produce green fluorescent protein (GFP) through its endogenous GPCR pathway. As a control region of GFP expression on the reporter plasmid, we focused on seven endogenous genes specifically activated through the pathway. When upstream regions of these genes were used as an inducible promoter in combination with LPI terminator, themam2upstream region produced GFP most rapidly and intensely despite the high background. Subsequently, LPI terminator was replaced with the corresponding downstream regions. The SPBC4.01 downstream region enhanced the response with the low background. Furthermore, combining SPBC4.01 downstream region with the sxa2 upstream region, the signal to noise ratio was obviously better than those of other regions. We also evaluated the time- and dose-dependent GFP productions of the strains transformed with the reporter plasmids. Finally, we exhibited a model of simplified GPCR assay with the reporter plasmid by expressing endogenous GPCR under the control of the foreign promoter.

Nuclear and subnuclear targeting sequences of the protein phosphatase-1 regulator NIPP1

2000 ◽  
Vol 113 (21) ◽  
pp. 3761-3768 ◽  
Author(s):  
I. Jagiello ◽  
A. Van Eynde ◽  
V. Vulsteke ◽  
M. Beullens ◽  
A. Boudrez ◽  
...  
Keyword(s):  
Active Transport ◽  
Protein Phosphatase ◽  
Enhanced Green Fluorescent Protein ◽  
Fluorescent Protein ◽  
Protein Phosphatase 1 ◽  
Splicing Factors ◽  
Nuclear Speckles ◽  
Nuclear Retention ◽  
Nuclear Localization Signals ◽  
Green Fluorescent

NIPP1 is a nuclear subunit of protein phosphatase-1 (PP1) that colocalizes with pre-mRNA splicing factors in speckles. We report here that the nuclear and subnuclear targeting of NIPP1, when expressed in HeLa cells or COS-1 cells as a fusion protein with the enhanced-green-fluorescent protein (EGFP), are mediated by distinct sequences. While NIPP1-EGFP can cross the nuclear membrane passively, the active transport to the nucleus is mediated by two independent nuclear localization signals in the central domain of NIPP1, which partially overlap with binding site(s) for PP1. Furthermore, the concentration of NIPP1-EGFP in the nuclear speckles requires the ‘ForkHead-Associated’ domain in the N terminus. This domain is also required for the nuclear retention of NIPP1 when active transport is blocked. Our data imply that the nuclear and subnuclear targeting of NIPP1 are controlled independently.

scholarly journals Specific Modification of Aged Proteasomes Revealed by Tag-Exchangeable Knock-In Mice

2018 ◽  
Vol 39 (1) ◽  
Author(s):  
Takuya Tomita ◽  
Shoshiro Hirayama ◽  
Yasuyuki Sakurai ◽  
Yuki Ohte ◽  
Hidehito Yoshihara ◽  
...  
Keyword(s):  
Cell Function ◽  
Fluorescent Protein ◽  
Embryonic Fibroblasts ◽  
Α Subunit ◽  
Biochemical Alterations ◽  
Cellular Processes ◽  
Responsible Gene ◽  
Intracellular Protein Degradation ◽  
Green Fluorescent

ABSTRACT The proteasome is the proteolytic machinery at the center of regulated intracellular protein degradation and participates in various cellular processes. Maintaining the quality of the proteasome is therefore important for proper cell function. It is unclear, however, how proteasomes change over time and how aged proteasomes are disposed. Here, we show that the proteasome undergoes specific biochemical alterations as it ages. We generated Rpn11-Flag/enhanced green fluorescent protein (EGFP) tag-exchangeable knock-in mice and established a method for selective purification of old proteasomes in terms of their molecular age at the time after synthesis. The half-life of proteasomes in mouse embryonic fibroblasts isolated from these knock-in mice was about 16 h. Using this tool, we found increased association of Txnl1, Usp14, and actin with the proteasome and specific phosphorylation of Rpn3 at Ser 6 in 3-day-old proteasomes. We also identified CSNK2A2 encoding the catalytic α′ subunit of casein kinase II (CK2α′) as a responsible gene that regulates the phosphorylation and turnover of old proteasomes. These findings will provide a basis for understanding the mechanism of molecular aging of the proteasome.

Sign in / Sign up

Export Citation Format

Share Document