scholarly journals Identifying and Characterizing a Novel Peritrophic Matrix Protein (MdPM-17) Associated With Antibacterial Response From the Housefly, Musca domestica (Diptera: Muscidae)

2020 ◽  
Vol 20 (6) ◽  
Author(s):  
Yu Wang ◽  
Jinzhi Cheng ◽  
Man Luo ◽  
Jianwei Wu ◽  
Guo Guo
Keyword(s):  
Amino Acid ◽  
Antimicrobial Peptide ◽  
Musca Domestica ◽  
Matrix Protein ◽  
Binding Capacity ◽  
Malpighian Tubule ◽  
Peritrophic Membrane ◽  
Distribution Analysis ◽  
Peritrophic Matrix ◽  
Amino Acid Residues

Abstract Peritrophic matrix/membrane (PM) critically prevents the midgut of insects from external invasion by microbes. The proteins in the peritrophic membrane are its major structural components. Additionally, they determine the formation and function of this membrane. However, the role of PM proteins in immune regulation is unclear. Herein, we isolated a novel PM protein (MdPM-17) from Musca domestica larvae. Further, the function of MdPM-17 in regulating host innate immunity was identified. Results showed that the cDNA of MdPM-17 full is 635 bp in length. Moreover, it consists of a 477-bp open reading frame encoding 158 amino acid residues. These amino acid residues are composed of two Chitin-binding type-2 domain (ChtBD2) and 19 amino acids as a signal peptide. Moreover, tissue distribution analysis indicates that MdPM-17 was enriched expressed in midgut, and moderate levels in the fat body, foregut, and malpighian tubule. Notably, MdPM-17 recombinant protein showed high chitin-binding capacity, thus belongs to the Class III PM protein group. MdPM-17 protein silencing via RNA interference resulted in the expression of antimicrobial peptide (defensin, cecropins, and diptericin) genes, and this occurred after oral inoculation with exogenous microbes Escherichia coli (Enterobacteriales:Enterobacteriaceae), Staphylococcus aureus (Bacillales:Staphylococcaceae), and Candida albicans (Endomycetales:Saccharomycetaceae)). Therefore, all the antimicrobial peptide (AMP) gene expression levels are high in MdPM-17-depleted larvae during microbial infection compared to controls. Consequently, these findings indicate that MdPM-17 protein is associated with the antibacterial response from the housefly.

scholarly journals Engineering dehydrated amino acid residues in the antimicrobial peptide nisin.

1992 ◽  
Vol 267 (34) ◽  
pp. 24340-24346
Author(s):  
O.P. Kuipers ◽  
H.S. Rollema ◽  
W.M. Yap ◽  
H.J. Boot ◽  
R.J. Siezen ◽  
...  
Keyword(s):  
Amino Acid ◽  
Antimicrobial Peptide ◽  
Amino Acid Residues

scholarly journals Two amino acid residues in the matrix protein M1 contribute to the virulence difference of H5N1 avian influenza viruses in mice

Virology ◽  
2009 ◽  
Vol 384 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Shufang Fan ◽  
Guohua Deng ◽  
Jiasheng Song ◽  
Guobin Tian ◽  
Yongbing Suo ◽  
...  
Keyword(s):  
Amino Acid ◽  
Avian Influenza ◽  
Matrix Protein ◽  
Influenza Viruses ◽  
Amino Acid Residues ◽  
Avian Influenza Viruses ◽  
H5n1 Avian Influenza ◽  
The Matrix ◽  
Matrix Protein M1

scholarly journals Effect of Point Mutations on Structural and Allergenic Properties of the Lentil Allergen Len c 3

Membranes ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 939
Author(s):  
Daria N. Melnikova ◽  
Ekaterina I. Finkina ◽  
Ivan V. Bogdanov ◽  
Anastasia A. Ignatova ◽  
Natalia S. Matveevskaya ◽  
...  
Keyword(s):  
Amino Acid ◽  
Binding Capacity ◽  
Point Mutations ◽  
Site Directed Mutagenesis ◽  
Amino Acid Residues ◽  
Lipid Transfer ◽  
Ige Binding ◽  
Allergenic Potential ◽  
Binding Epitope ◽  
Clinically Significant

Plant lipid transfer proteins (LTPs) are known to be clinically significant allergens capable of binding various lipid ligands. Recent data showed that lipid ligands affected the allergenic properties of plant LTPs. In this work, we checked the assumption that specific amino acid residues in the Len c 3 structure can play a key role both in the interaction with lipid ligands and IgE-binding capacity of the allergen. The recombinant analogues of Len c 3 with the single or double substitutions of Thr41, Arg45 and/or Tyr80 were obtained by site-directed mutagenesis. All these amino acid residues are located near the “bottom” entrance to the hydrophobic cavity of Len c 3 and are likely included in the IgE-binding epitope of the allergen. Using a bioinformatic approach, circular dichroism and fluorescence spectroscopies, ELISA, and experiments mimicking the allergen Len c 3 gastroduodenal digestion we showed that the substitution of all the three amino acid residues significantly affected structural organization of this region and led both to a change of the ligand-binding capacity and the allergenic potential of Len c 3.

Mutational analysis of hepatitis C virus NS3-associated helicase

Microbiology ◽  
2000 ◽  
Vol 81 (7) ◽  
pp. 1649-1658 ◽  
Author(s):  
Chantal Paolini ◽  
Armin Lahm ◽  
Raffaele De Francesco ◽  
Paola Gallinari
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Amino Acid ◽  
Atpase Activity ◽  
Mutational Analysis ◽  
Nonstructural Protein ◽  
Binding Capacity ◽  
Molecular Model ◽  
Helicase Domain ◽  
Amino Acid Residues

Nonstructural protein 3 (NS3) of hepatitis C virus contains a bipartite structure consisting of an N-terminal serine protease and a C-terminal DEXH box helicase. To investigate the roles of individual amino acid residues in the overall mechanism of unwinding, a mutational–functional analysis was performed based on a molecular model of the NS3 helicase domain bound to ssDNA, which has largely been confirmed by a recently published crystal structure of the NS3 helicase–ssDNA complex. Three full-length mutated NS3 proteins containing Tyr(392)Ala, Val(432)Gly and Trp(501)Ala single substitutions, respectively, together with a Tyr(392)Ala/Trp(501)Ala double-substituted protein were expressed in Escherichia coli and purified to homogeneity. All individually mutated forms showed a reduction in duplex unwinding activity, single-stranded polynucleotide binding capacity and polynucleotide-stimulated ATPase activity compared to wild-type, though to different extents. Simultaneous replacement of both Tyr392 and Trp501 with Ala completely abolished all these enzymatic functions. On the other hand, the introduced amino acid substitutions had no influence on NS3 intrinsic ATPase activity and proteolytic efficiency. The results obtained with Trp(501)Ala and Val(432)Gly single-substituted enzymes are in agreement with a recently proposed model for NS3 unwinding activity. The mutant phenotype of the Tyr(392)Ala and Tyr(392)Ala/Trp(501)Ala enzymes, however, represents a completely novel finding.

scholarly journals Analysis of Mason-Pfizer Monkey Virus Gag Domains Required for Capsid Assembly in Bacteria: Role of the N-Terminal Proline Residue of CA in Directing Particle Shape

2000 ◽  
Vol 74 (18) ◽  
pp. 8452-8459 ◽  
Author(s):  
Michaela Rumlova-Klikova ◽  
Eric Hunter ◽  
Milan V. Nermut ◽  
Iva Pichova ◽  
Tomas Ruml
Keyword(s):  
Amino Acid ◽  
Nucleocapsid Protein ◽  
Mammalian Cells ◽  
Matrix Protein ◽  
Amino Acid Residues ◽  
Membrane Expression ◽  
Specific Amino Acid ◽  
Plasma Membrane Expression ◽  
C And N

ABSTRACT Mason-Pfizer monkey virus (M-PMV) preassembles immature capsids in the cytoplasm prior to transporting them to the plasma membrane. Expression of the M-PMV Gag precursor in bacteria results in the assembly of capsids indistinguishable from those assembled in mammalian cells. We have used this system to investigate the structural requirements for the assembly of Gag precursors into procapsids. A series of C- and N-terminal deletion mutants progressively lacking each of the mature Gag domains (matrix protein [MA]-pp24/16-p12-capsid protein [CA]-nucleocapsid protein [NC]-p4) were constructed and expressed in bacteria. The results demonstrate that both the CA and the NC domains are necessary for the assembly of macromolecular arrays (sheets) but that amino acid residues at the N terminus of CA define the assembly of spherical capsids. The role of these N-terminal domains is not based on a specific amino acid sequence, since both MA-CA-NC and p12-CA-NC polyproteins efficiently assemble into capsids. Residues N terminal of CA appear to prevent a conformational change in which the N-terminal proline plays a key role, since the expression of a CA-NC protein lacking this proline results in the assembly of spherical capsids in place of the sheets assembled by the CA-NC protein.

A Soluble Recombinant Factor VIII Fragment Containing the A2 Domain Binds to Some Human Anti-Factor VIII Antibodies that Are not Detected by Immunoblotting

1992 ◽  
Vol 67 (06) ◽  
pp. 665-671 ◽  
Author(s):  
Dorothea Scandella ◽  
Lisa Timmons ◽  
Mora Mattingly ◽  
Norma Trabold ◽  
Leon W Hoyer
Keyword(s):  
Amino Acid ◽  
Factor Viii ◽  
Human Factor ◽  
Binding Capacity ◽  
Amino Acid Residues ◽  
Protein Fragment ◽  
Immunoprecipitation Assay ◽  
Human Factor Viii ◽  
A2 Domain

SummaryHuman factor VIII (f VIII) inhibitors are pathologic antibodies that inactivate fVIII. A cDNA clone was modified to encode f VIII amino acid residues 373-740 for expression in a baculovirus vector in insect cells. The encoded protein fragment H2 was produced as a soluble, secreted protein, and it was used to test inhibitor plasmas for the presence of antibodies that were not detected by immunoblotting. Seven of 13 inhibitors that bound, only to the fVIII light chain by immunoblotting also bound to fragment H2 in an immunoprecipitation assay. Thus multi-chain inhibitor reactivity of inhibitors is more frequent than previously reported. One of these inhibitors was shown to share the epitope for other inhibitors that bind to H2 within amino acid residues 373-541 in immunoblotting assays. The sensitive immunoprecipitation assay described allows determination of relative H2 binding capacity of the total IgG and epitope localization of inhibitors that cannot be similarly characterized by immunoblotting.

scholarly journals Identification of amino acid residues critical for the B cell growth-promoting activity of HIV-1 matrix protein p17 variants

2019 ◽  
Vol 1863 (1) ◽  
pp. 13-24 ◽  
Author(s):  
Wangxiao He ◽  
Pietro Mazzuca ◽  
Weirong Yuan ◽  
Kristen Varney ◽  
Antonella Bugatti ◽  
...  
Keyword(s):  
Amino Acid ◽  
Cell Growth ◽  
B Cell ◽  
Matrix Protein ◽  
Amino Acid Residues ◽  
Growth Promoting ◽  
Hiv 1

scholarly journals Structural Phosphoprotein M2-1 of the Human Respiratory Syncytial Virus Is an RNA Binding Protein

2000 ◽  
Vol 74 (21) ◽  
pp. 9858-9867 ◽  
Author(s):  
Isabel Cuesta ◽  
Xuehui Geng ◽  
Ana Asenjo ◽  
Nieves Villanueva
Keyword(s):  
Respiratory Syncytial Virus ◽  
Amino Acid ◽  
Rna Binding ◽  
Protein Complexes ◽  
Binding Capacity ◽  
Human Respiratory Syncytial Virus ◽  
Sequence Specificity ◽  
Amino Acid Residues ◽  
Syncytial Virus ◽  
Rna Protein Complexes

ABSTRACT The structural phosphoprotein M2-1 of human respiratory syncytial virus (HRSV) Long strain shows RNA binding capacity in three different assays that detect RNA-protein complexes: cross-linking, gel retardation, and Northern-Western assays. It is able to bind HRSV leader RNA specifically with cooperative kinetics, with an apparentKd of at least 90 nM. It also binds to long RNAs with no sequence specificity. The RNA binding domain has been located between amino acid residues 59 and 85, at the NH2terminus of the protein. This region contains the phosphorylatable amino acid residues threonine 56 and serine 58, whose modification decreases the binding capacity of M2-1 protein to long RNAs.

scholarly journals Interaction of truncated human interferon γ variants with the interferon γ receptor: crucial importance of Arg-129

1997 ◽  
Vol 324 (2) ◽  
pp. 591-595 ◽  
Author(s):  
Joost HAELEWYN ◽  
Lieve MICHIELS ◽  
Peter VERHAERT ◽  
Marc F. HOYLAERTS ◽  
Raphaël WITTERS ◽  
...  
Keyword(s):  
Amino Acid ◽  
Binding Capacity ◽  
Interferon Γ ◽  
Receptor Interaction ◽  
Human Interferon ◽  
Amino Acid Residues ◽  
Surface Plasmon Resonance Analysis ◽  
Resonance Analysis ◽  
C Terminus ◽  
Ifn Γ

Recombinant human interferon γ (IFN-γ), produced in Escherichia coli, was selectively truncated at its C-terminus with chymotrypsin, clostripain or plasmin. The C-terminal amino acid residues of the three truncated IFN-γ variants were identified as Phe136, Arg129 and Lys128, indicating the removal of 7, 14 and 15 amino acid residues from the full-length molecule. The absence of seven C-terminal residues did not influence the binding of IFN-γ to its receptor. In contrast, the truncation of 14 residues resulted in a decrease in the Ka value to 1/24, as determined by surface plasmon resonance analysis. The removal of one additional amino acid residue from the C-terminal region of IFN-γ led to a marked loss of receptor-binding capacity and biological activity. These observations demonstrate that Arg129 is an essential part of a functionally important C-terminal IFN-γ sequence that is involved in receptor interaction.

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