scholarly journals Identification of the B1 and B2 subunits of human placental laminin and rat parietal-yolk-sac laminin using antisera specific for murine laminin-β-galactosidase fusion proteins

1990 ◽  
Vol 270 (2) ◽  
pp. 463-468 ◽  
Author(s):  
J C Brown ◽  
J H Spragg ◽  
G N Wheeler ◽  
P W Taylor
Keyword(s):  
Escherichia Coli ◽  
Fusion Protein ◽  
Fusion Proteins ◽  
Yolk Sac ◽  
Western Blots ◽  
C Terminus ◽  
Sds Page ◽  
A Subunit ◽  
B Subunits ◽  
Beta Galactosidase

Antisera raised against fusion proteins consisting of murine laminin B1 and B2 subunit sequences fused to the C-terminus of Escherichia coli beta-galactosidase were tested for their subunit specificity on Western blots of deglycosylated murine Engelbreth-Holm-Swarm (EHS) laminin. The antisera raised against B2 subunit sequences (anti-XLB2.1 and anti-XLB2.2) bound only to the EHS laminin B2 subunit. One of the antisera raised against B1 subunit sequences (anti-XLB1.2) was specific for the B1 subunit, whereas two others (anti-XLB1.1 and anti-XLB1.3) cross-reacted with the EHS laminin B2 subunit. Gold-labelled heparin-albumin was shown to bind specifically to the A subunit of deglycosylated EHS laminin on Western blots. These reagents were used to identify the homologous subunits in rat parietal-yolk-sac laminin and human placental laminin. The anti-(fusion protein) antisera identified the B1 and B2 subunits of the rat laminin, and these were similar in size to the murine EHS B subunits. Human placental laminin gave bands of 400, 340, 230, 190 and 180 kDa on reducing SDS/PAGE. The anti-(fusion protein) antisera identified the 230 and 190 kDa bands as the B1 and B2 subunits respectively. Gold-labelled heparin-albumin bound to the 400, 340 and 190 kDa bands of human placental laminin and so did not unambiguously identify a single A subunit. The human placental laminin may contain a mixture of isoforms, with alternative subunits substituting for the A subunit.

scholarly journals Monoclonal antibodies specific for the C-terminus of the laminin B2 subunit. Evidence for glycosylation differences between murine and human laminin

1991 ◽  
Vol 277 (3) ◽  
pp. 593-596
Author(s):  
J C Brown ◽  
J H Spragg ◽  
P W Taylor
Keyword(s):  
Amino Acids ◽  
Monoclonal Antibodies ◽  
Fusion Protein ◽  
Adult Mouse ◽  
Yolk Sac ◽  
Specific Difference ◽  
C Terminus ◽  
Mouse Tissues ◽  
Species Specific ◽  
Beta Galactosidase

We have raised a panel of monoclonal antibodies against a beta-galactosidase fusion protein (XLB2.1) containing the C-terminal 153 amino acids of the murine laminin B2 subunit. Five of the nine antibodies characterized recognize human placental laminin as well as murine Engelbreth-Holm-Swarm (EHS)-tumour laminin. Only two of the antibodies recognize both rat parietal-yolk-sac laminin and murine EHS-tumour laminin. Two antibodies recognize an epitope on the human laminin B2 subunit which is masked by N-linked oligosaccharide in murine EHS-tumour laminin. These antibodies also fail to bind to laminin from adult-mouse tissues. These results demonstrate a species-specific difference in the glycosylation of the laminin B2 subunit.

Expression of a Fusion Protein of Human Proinsulin with Glutathione-S-Transferase in Escherichia coli

2014 ◽  
Vol 998-999 ◽  
pp. 248-251
Author(s):  
Zhi Xin Di ◽  
Jian Zhong Ma ◽  
Yong Gang Wang
Keyword(s):  
Escherichia Coli ◽  
Fusion Protein ◽  
Fusion Proteins ◽  
Inclusion Bodies ◽  
Glutathione S Transferase ◽  
E Coli ◽  
Human Proinsulin ◽  
Sds Page ◽  
Dna Fragment ◽  
Sequence Encoding

A DNA sequence encoding for the human proinsulin was designed according to the codon bias of Escherichia coli and then chemically synthesized. The synthesized DNA fragment was subcloned into pGEX-3X for expression in E. coli BL21 (DE3) and E. coli BL21 Star (DE3), respectively. Conditions for the highest expression of the GST-proinsulin fusion proteins were optimized. These conditions are that cells of E. coli BL21 star (DE3) are incubated in 100mL of the LB medium with 2 mmol/L IPTG and 60μ?g/mL ampicillin at 26oCfor 4h. After disrupted E. coli cells with ultrasonication, inclusion bodies were precipitated from cell lysis and washed. Fusion proteins from the inclusion bodies were redissolved in 8mmol/L of urea. After dialysed in purified water, fusion proteins were analysed by SDS-PAGE. The purity of the fusion protein is about 80.5% in total. The fusion protein from SDS-PAGE was further identified by mass/mass spectrum. GST in the dyad protein is confirmed by the 9 matched sequences. However, the left part is proved a polypeptide of which is completely different from the human proinsulin.

scholarly journals Molecular and Biochemical Characterization of the xlnD-Encoded 3-Hydroxybenzoate 6-Hydroxylase Involved in the Degradation of 2,5-Xylenol via the Gentisate Pathway in Pseudomonas alcaligenes NCIMB 9867

2005 ◽  
Vol 187 (22) ◽  
pp. 7696-7702 ◽  
Author(s):  
Xiaoli Gao ◽  
Chew Ling Tan ◽  
Chew Chieng Yeo ◽  
Chit Laa Poh
Keyword(s):  
Escherichia Coli ◽  
Fusion Protein ◽  
Molecular Mass ◽  
Electron Donor ◽  
Biochemical Characterization ◽  
Aromatic Substrates ◽  
Gentisate Pathway ◽  
A Subunit ◽  
Pseudomonas Alcaligenes

ABSTRACT The xlnD gene from Pseudomonas alcaligenes NCIMB 9867 (strain P25X) was shown to encode 3-hydroxybenzoate 6-hydroxylase I, the enzyme that catalyzes the NADH-dependent conversion of 3-hydroxybenzoate to gentisate. Active recombinant XlnD was purified as a hexahistidine fusion protein from Escherichia coli, had an estimated molecular mass of 130 kDa, and is probably a trimeric protein with a subunit mass of 43 kDa. This is in contrast to the monomeric nature of the few 3-hydroxybenzoate 6-hydroxylases that have been characterized thus far. Like other 3-hydroxybenzoate 6-hydroxylases, XlnD could utilize either NADH or NADPH as the electron donor. P25X harbors a second 3-hydroxybenzoate 6-hydroxylase II that was strictly inducible by specific aromatic substrates. However, the degradation of 2,5-xylenol and 3,5-xylenol in strain P25X was found to be dependent on the xlnD-encoded 6-hydroxylase I and not the second, strictly inducible 6-hydroxylase II.

scholarly journals An Archaeal Photosignal-Transducing Module Mediates Phototaxis in Escherichia coli

2001 ◽  
Vol 183 (21) ◽  
pp. 6365-6371 ◽  
Author(s):  
Kwang-Hwan Jung ◽  
Elena N. Spudich ◽  
Vishwa D. Trivedi ◽  
John L. Spudich
Keyword(s):  
Escherichia Coli ◽  
Fusion Protein ◽  
Current Model ◽  
Halophilic Archaea ◽  
Halobacterium Salinarum ◽  
Cytoplasmic Domains ◽  
Transmembrane Segments ◽  
C Terminus ◽  
Reaction Cycles

ABSTRACT Halophilic archaea, such as Halobacterium salinarumand Natronobacterium pharaonis, alter their swimming behavior by phototaxis responses to changes in light intensity and color using visual pigment-like sensory rhodopsins (SRs). In N. pharaonis, SRII (NpSRII) mediates photorepellent responses through its transducer protein, NpHtrII. Here we report the expression of fusions of NpSRII and NpHtrII and fusion hybrids with eubacterial cytoplasmic domains and analyze their function in vivo in haloarchaea and in eubacteria. A fusion in which the C terminus of NpSRII is connected by a short flexible linker to NpHtrII is active in phototaxis signaling for H. salinarum, showing that the fusion does not inhibit functional receptor-transducer interactions. We replaced the cytoplasmic portions of this fusion protein with the cytoplasmic domains of Tar and Tsr, chemotaxis transducers from enteric eubacteria. Purification of the fusion protein from H. salinarum and Tar fusion chimera from Escherichia coli membranes shows that the proteins are not cleaved and exhibit absorption spectra characteristic of wild-type membranes. Their photochemical reaction cycles in H. salinarum and E. coli membranes, respectively, are similar to those of native NpSRII in N. pharaonis. These fusion chimeras mediate retinal-dependent phototaxis responses by Escherichia coli, establishing that the nine-helix membrane portion of the receptor-transducer complex is a modular functional unit able to signal in heterologous membranes. This result confirms a current model for SR-Htr signal transduction in which the Htr transducers are proposed to interact physically and functionally with their cognate sensory rhodopsins via helix-helix contacts between their transmembrane segments.

scholarly journals Autodisplay: Functional Display of Active β-Lactamase on the Surface of Escherichia coli by the AIDA-I Autotransporter

2000 ◽  
Vol 182 (13) ◽  
pp. 3726-3733 ◽  
Author(s):  
Claus T. Lattemann ◽  
Jochen Maurer ◽  
Elke Gerland ◽  
Thomas F. Meyer
Keyword(s):  
Escherichia Coli ◽  
Fusion Protein ◽  
Surface Display ◽  
Heterologous Proteins ◽  
Bacterial Surface ◽  
E Coli ◽  
C Terminus ◽  
Protease Treatment ◽  
Efficient Expression ◽  
Cell Envelopes

ABSTRACT Members of the protein family of immunoglobulin A1 protease-like autotransporters comprise multidomain precursors consisting of a C-terminal autotransporter domain that promotes the translocation of N-terminally attached passenger domains across the cell envelopes of gram-negative bacteria. Several autotransporter domains have recently been shown to efficiently promote the export of heterologous passenger domains, opening up an effective tool for surface display of heterologous proteins. Here we report on the autotransporter domain of the Escherichia coli adhesin involved in diffuse adherence (AIDA-I), which was genetically fused to the C terminus of the periplasmic enzyme β-lactamase, leading to efficient expression of the fusion protein in E. coli. The β-lactamase moiety of the fusion protein was presented on the bacterial surface in a stable manner, and the surface-located β-lactamase was shown to be enzymatically active. Enzymatic activity was completely removed by protease treatment, indicating that surface display of β-lactamase was almost quantitative. The periplasmic domain of the outer membrane protein OmpA was not affected by externally added proteases, demonstrating that the outer membranes of E. coli cells expressing the β-lactamase AIDA-I fusion protein remained physiologically intact.

scholarly journals Development of a single-stranded DNA-binding protein fluorescent fusion toolbox

2020 ◽  
Vol 48 (11) ◽  
pp. 6053-6067
Author(s):  
Katarzyna Dubiel ◽  
Camille Henry ◽  
Lisanne M Spenkelink ◽  
Alexander G Kozlov ◽  
Elizabeth A Wood ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Replication ◽  
Dna Binding ◽  
Single Molecule ◽  
Fusion Proteins ◽  
Fluorescent Protein ◽  
Single Stranded Dna ◽  
Intrinsically Disordered ◽  
C Terminus ◽  
Sites Of Action

Abstract Bacterial single-stranded DNA-binding proteins (SSBs) bind single-stranded DNA and help to recruit heterologous proteins to their sites of action. SSBs perform these essential functions through a modular structural architecture: the N-terminal domain comprises a DNA binding/tetramerization element whereas the C-terminus forms an intrinsically disordered linker (IDL) capped by a protein-interacting SSB-Ct motif. Here we examine the activities of SSB-IDL fusion proteins in which fluorescent domains are inserted within the IDL of Escherichia coli SSB. The SSB-IDL fusions maintain DNA and protein binding activities in vitro, although cooperative DNA binding is impaired. In contrast, an SSB variant with a fluorescent protein attached directly to the C-terminus that is similar to fusions used in previous studies displayed dysfunctional protein interaction activity. The SSB-IDL fusions are readily visualized in single-molecule DNA replication reactions. Escherichia coli strains in which wildtype SSB is replaced by SSB-IDL fusions are viable and display normal growth rates and fitness. The SSB-IDL fusions form detectible SSB foci in cells with frequencies mirroring previously examined fluorescent DNA replication fusion proteins. Cells expressing SSB-IDL fusions are sensitized to some DNA damaging agents. The results highlight the utility of SSB-IDL fusions for biochemical and cellular studies of genome maintenance reactions.

scholarly journals A DNA Vaccine Encoding the Enterohemorragic Escherichia coli Shiga-Like Toxin 2 A2 and B Subunits Confers Protective Immunity to Shiga Toxin Challenge in the Murine Model

2009 ◽  
Vol 16 (5) ◽  
pp. 712-718 ◽  
Author(s):  
Leticia V. Bentancor ◽  
Marcos Bilen ◽  
Romina J. Fernández Brando ◽  
María Victoria Ramos ◽  
Luis C. S. Ferreira ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Dna Vaccine ◽  
Protective Immunity ◽  
Host Cells ◽  
Therapeutic Interventions ◽  
28S Rrna ◽  
A Subunit ◽  
B Subunits

ABSTRACT Production of verocytotoxin or Shiga-like toxin (Stx), particularly Stx2, is the basis of hemolytic uremic syndrome, a frequently lethal outcome for subjects infected with Stx2-producing enterohemorrhagic Escherichia coli (EHEC) strains. The toxin is formed by a single A subunit, which promotes protein synthesis inhibition in eukaryotic cells, and five B subunits, which bind to globotriaosylceramide at the surface of host cells. Host enzymes cleave the A subunit into the A1 peptide, endowed with N-glycosidase activity to the 28S rRNA, and the A2 peptide, which confers stability to the B pentamer. We report the construction of a DNA vaccine (pStx2ΔAB) that expresses a nontoxic Stx2 mutated form consisting of the last 32 amino acids of the A2 sequence and the complete B subunit as two nonfused polypeptides. Immunization trials carried out with the DNA vaccine in BALB/c mice, alone or in combination with another DNA vaccine encoding granulocyte-macrophage colony-stimulating factor, resulted in systemic Stx-specific antibody responses targeting both A and B subunits of the native Stx2. Moreover, anti-Stx2 antibodies raised in mice immunized with pStx2ΔAB showed toxin neutralization activity in vitro and, more importantly, conferred partial protection to Stx2 challenge in vivo. The present vector represents the second DNA vaccine so far reported to induce protective immunity to Stx2 and may contribute, either alone or in combination with other procedures, to the development of prophylactic or therapeutic interventions aiming to ameliorate EHEC infection-associated sequelae.

scholarly journals Expression in Bacteria of the Gene Encoding the gp43 Antigen of Paracoccidioides brasiliensis: Immunological Reactivity of the Recombinant Fusion Proteins

2002 ◽  
Vol 9 (6) ◽  
pp. 1200-1204 ◽  
Author(s):  
Susana N. Diniz ◽  
Kátia C. Carvalho ◽  
Patrícia S. Cisalpino ◽  
José F. Silveira ◽  
Luiz R. Travassos ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Fusion Protein ◽  
Fusion Proteins ◽  
Inclusion Bodies ◽  
Paracoccidioides Brasiliensis ◽  
Immunological Reactivity ◽  
Gene Encoding ◽  
Recombinant Fusion Proteins ◽  
Gst Fusion Protein

ABSTRACT gp43 is the major diagnostic antigen of Paracoccidioides brasiliensis, the agent of paracoccidioidomycosis (PCM) in humans. In the present study, cDNA of the gp43 gene (PbGP43) was obtained by reverse transcriptase PCR, inserted into a pGEX vector in frame with the glutathione S-transferase (GST) gene, and expressed in Escherichia coli as inclusion bodies. Immunoblotting showed that all sera from patients with chronic pulmonary and acute lymphatic forms of PCM reacted with the recombinant fusion protein of the mature gp43 (381 amino acids). Reactivity with fusion proteins containing subfragments of the N-terminal, internal, or C-terminal regions occurred eventually, and the C-terminal region was the most antigenic. Lack of reactivity with the subfragments may be due to the conformational nature of the gp43 epitopes. Sera from patients with aspergillosis, candidiasis, and histoplasmosis did not react with the gp43-GST fusion protein. Our results suggest that recombinant gp43 corresponding to the processed antigen can be a useful tool in the diagnosis of PCM.

scholarly journals Study on Cecropin B2 Production via Construct Bearing Intein Oligopeptide Cleavage Variants

Molecules ◽  
2020 ◽  
Vol 25 (4) ◽  
pp. 1005
Author(s):  
Yi-Ting Fang ◽  
Si-Yu Li ◽  
Nien-Jen Hu ◽  
Jie Yang ◽  
Jyung-Hurng Liu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Fusion Protein ◽  
Md Simulation ◽  
Cleavage Reaction ◽  
Chitin Binding Domain ◽  
First Order ◽  
C Terminus ◽  
Efficient Performance ◽  
Order Rate Equation

In this study, genetic engineering was applied to the overexpression of the antimicrobial peptide (AMP) cecropin B2 (cecB2). pTWIN1 vector with a chitin-binding domain (CBD) and an auto-cleavage Ssp DnaB intein (INT) was coupled to the cecB2 to form a fusion protein construct and expressed via Escherichia coli ER2566. The cecB2 was obtained via the INT cleavage reaction, which was highly related to its adjacent amino acids. Three oligopeptide cleavage variants (OCVs), i.e., GRA, CRA, and SRA, were used as the inserts located at the C-terminus of the INT to facilitate the cleavage reaction. SRA showed the most efficient performance in accelerating the INT self-cleavage reaction. In addition, in order to treat the INT as a biocatalyst, a first-order rate equation was applied to fit the INT cleavage reaction. A possible inference was proposed for the INT cleavage promotion with varied OCVs using a molecular dynamics (MD) simulation. The production and purification via the CBD-INT-SRA-cecB2 fusion protein resulted in a cecB2 yield of 58.7 mg/L with antimicrobial activity.

Production and characterization of recombinant insulin-like growth factor-I (IGF-I) and potent analogues of IGF-I, with Gly or Arg substituted for Glu 3, following their expression in Escherichia coli as fusion proteins

1992 ◽  
Vol 8 (1) ◽  
pp. 29-41 ◽  
Author(s):  
R. King ◽  
J. R. E. Wells ◽  
P. Krieg ◽  
M. Snoswell ◽  
J. Brazier ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Growth Factor ◽  
Fusion Protein ◽  
Fusion Proteins ◽  
Expression System ◽  
Insulin Like Growth Factor ◽  
Factor I ◽  
Igf I ◽  
Igf Binding ◽  
Growth Factor I

ABSTRACT The development of an efficient expression system for insulin-like growth factor-I (IGF-I) in Escherichia coli as a fusion protein is described. The fusion protein consists of an N-terminal extension made up of the first 46 amino acids of methionyl porcine GH ([Met1]-pGH) followed by the dipeptide Val-Asn. The latter two residues provide a unique hydroxylamine-sensitive link between [Met1]-pGH(1-46) and the N-terminal Gly of IGF-I. Downstream processing of the fusion proteins involved isolation of inclusion bodies, cleavage at the Asn-Gly bond, refolding of the reduced IGF-I peptide and purification to homogeneity. This expression system was also used to produce two variants of IGF-I in which Glu3 was substituted by either Gly or Arg to give [Gly3]-IGF-I and [Arg3]-IGF-I respectively. Production of milligram quantities of IGF-I peptide was readily achieved. The purity of the IGF-I, [Gly3]-IGF-I and [Arg3]-IGF-I was established by high-performance liquid chromatography and N-terminal sequence analysis. [Gly3]-IGF-I and [Arg3]-IGF-I were more potent than IGF-I in biological assays measuring stimulation of protein synthesis and DNA synthesis or inhibition of protein breakdown in rat L6 myoblasts. Both analogues bound very poorly to bovine IGF-binding protein-2 and slightly less well than IGF-I to the type-1 receptor on rat L6 myoblasts. We conclude that reduced binding to IGF-binding proteins rather than increased receptor binding is the likely explanation for the greater biological potency of the analogues compared with IGF-I.

Sign in / Sign up

Export Citation Format

Share Document