scholarly journals Peptide Mimic of Phosphorylcholine, a Dominant Epitope Found on Streptococcus pneumoniae

2000 ◽  
Vol 68 (10) ◽  
pp. 5778-5784 ◽  
Author(s):  
Shannon L. Harris ◽  
Moon K. Park ◽  
Moon H. Nahm ◽  
Betty Diamond
Keyword(s):  
Streptococcus Pneumoniae ◽  
Amino Acid ◽  
Binding Site ◽  
The Elderly ◽  
Cross Reactivity ◽  
Amino Acid Sequences ◽  
Pneumococcal Infections ◽  
Amino Acid Region ◽  
Peptide Mimic ◽  
Idiotypic Interaction

ABSTRACT Even in the age of antibiotics, Streptococcus pneumoniae causes significant morbidity, especially in the young, the elderly, and the immunocompromised. While a carbohydrate-based vaccine exists, it is poorly immunogenic in the at-risk populations. In mice, antibodies directed against phosphorylcholine (PC), an epitope present on the cell wall C polysaccharide of all pneumococcal serotypes, protect against infection. However, PC itself is a poor vaccine candidate. We report here peptide mimics of PC based on the anti-idiotypic interaction of T15 anti-PC antibodies. T15 antibodies, the dominant and protective idiotype induced in mice by PC immunization, self-associate via a 24-amino-acid region in the PC binding site (ASRNKANDYTTEYSASVKGRFIVS; peptide 1). Peptide 1 has been shown to bind in the PC binding site. We demonstrated that amino acid sequences derived from peptide 1 starting at amino acid 9, 11, or 13 inhibit PC binding. Therefore, we immunized mice with bovine serum albumin (BSA) conjugates of peptide 1 or either of two selected 12-mers. The 12-mer peptides were not immunogenic. Mice immunized with peptide 1-BSA developed an anti-PC response consisting mainly immunoglobulin G1 and expressed the T15 heavy chain. Nonetheless, neither BALB/c nor CBA/N mice were protected from lethal pneumococcal infections by immunization with peptide 1-BSA. Preliminary data suggest that peptide 1-BSA is not able to elicit the canonical T15 light chain, explaining the absence of protection. This idiotype-derived mimotope of PC is a useful tool for understanding immunologic cross-reactivity and learning to design T-cell-dependent vaccines for S. pneumoniae.

scholarly journals Genetic and antigenic diversity among noroviruses

2006 ◽  
Vol 87 (4) ◽  
pp. 909-919 ◽  
Author(s):  
Grant S. Hansman ◽  
Katsuro Natori ◽  
Haruko Shirato-Horikoshi ◽  
Satoko Ogawa ◽  
Tomoichiro Oka ◽  
...  
Keyword(s):  
Amino Acid ◽  
Insect Cells ◽  
Phylogenetic Analyses ◽  
Cross Reactivity ◽  
Amino Acid Sequences ◽  
Amino Acid Residues ◽  
Cell Culture Systems ◽  
Antibody Elisa ◽  
Polyclonal Antisera ◽  
Antigenic Relationships

Human norovirus (NoV) strains cause a considerable number of outbreaks of gastroenteritis worldwide. Based on their capsid gene (VP1) sequence, human NoV strains can be grouped into two genogroups (GI and GII) and at least 14 GI and 17 GII genotypes (GI/1–14 and GII/1–17). Human NoV strains cannot be propagated in cell-culture systems, but expression of recombinant VP1 in insect cells results in the formation of virus-like particles (VLPs). In order to understand NoV antigenic relationships better, cross-reactivity among 26 different NoV VLPs was analysed. Phylogenetic analyses grouped these NoV strains into six GI and 12 GII genotypes. An antibody ELISA using polyclonal antisera raised against these VLPs was used to determine cross-reactivity. Antisera reacted strongly with homologous VLPs; however, a number of novel cross-reactivities among different genotypes was observed. For example, GI/11 antiserum showed a broad-range cross-reactivity, detecting two GI and 10 GII genotypes. Likewise, GII/1, GII/10 and GII/12 antisera showed a broad-range cross-reactivity, detecting several other distinct GII genotypes. Alignment of VP1 amino acid sequences suggested that these broad-range cross-reactivities were due to conserved amino acid residues located within the shell and/or P1-1 domains. However, unusual cross-reactivities among different GII/3 antisera were found, with the results indicating that both conserved amino acid residues and VP1 secondary structures influence antigenicity.

scholarly journals Analysis of a nucleotide-binding site of 5-lipoxygenase by affinity labelling: binding characteristics and amino acid sequences

2000 ◽  
Vol 351 (3) ◽  
pp. 697 ◽  
Author(s):  
Ying-Yi ZHANG ◽  
Tove HAMMARBERG ◽  
Olof RADMARK ◽  
Bengt SAMUELSSON ◽  
Carol F. NG ◽  
...  
Keyword(s):  
Amino Acid ◽  
Binding Site ◽  
Nucleotide Binding ◽  
Amino Acid Sequences ◽  
Nucleotide Binding Site ◽  
Binding Characteristics ◽  
Affinity Labelling

scholarly journals Analysis of a nucleotide-binding site of 5-lipoxygenase by affinity labelling: binding characteristics and amino acid sequences

2000 ◽  
Vol 351 (3) ◽  
pp. 697-707 ◽  
Author(s):  
Ying-Yi ZHANG ◽  
Tove HAMMARBERG ◽  
Olof RADMARK ◽  
Bengt SAMUELSSON ◽  
Carol F. NG ◽  
...  
Keyword(s):  
Amino Acid ◽  
Binding Site ◽  
Tertiary Structure ◽  
Nucleotide Binding ◽  
Peptide Sequencing ◽  
Amino Acid Sequences ◽  
Nucleotide Binding Site ◽  
Atp Binding ◽  
Binding Characteristics ◽  
Atp Binding Site

5-Lipoxygenase (5LO) catalyses the first two steps in the biosynthesis of leukotrienes, which are inflammatory mediators derived from arachidonic acid. 5LO activity is stimulated by ATP; however, a consensus ATP-binding site or nucleotide-binding site has not been found in its protein sequence. In the present study, affinity and photoaffinity labelling of 5LO with 5′-p-fluorosulphonylbenzoyladenosine (FSBA) and 2-azido-ATP showed that 5LO bound to the ATP analogues quantitatively and specifically and that the incorporation of either analogue inhibited ATP stimulation of 5LO activity. The stoichiometry of the labelling was 1.4mol of FSBA/mol of 5LO (of which ATP competed with 1mol/mol) or 0.94mol of 2-azido-ATP/mol of 5LO (of which ATP competed with 0.77mol/mol). Labelling with FSBA prevented further labelling with 2-azido-ATP, indicating that the same binding site was occupied by both analogues. Other nucleotides (ADP, AMP, GTP, CTP and UTP) also competed with 2-azido-ATP labelling, suggesting that the site was a general nucleotide-binding site rather than a strict ATP-binding site. Ca2+, which also stimulates 5LO activity, had no effect on the labelling of the nucleotide-binding site. Digestion with trypsin and peptide sequencing showed that two fragments of 5LO were labelled by 2-azido-ATP. These fragments correspond to residues 73–83 (KYWLNDDWYLK, in single-letter amino acid code) and 193–209 (FMHMFQSSWNDFADFEK) in the 5LO sequence. Trp-75 and Trp-201 in these peptides were modified by the labelling, suggesting that they were immediately adjacent to the C-2 position of the adenine ring of ATP. Given the stoichiometry of the labelling, the two peptide sequences of 5LO were probably near each other in the enzyme's tertiary structure, composing or surrounding the ATP-binding site of 5LO.

scholarly journals Molecular cloning of a cDNA encoding the glycoprotein of hen oviduct microsomal signal peptidase

1992 ◽  
Vol 282 (2) ◽  
pp. 447-452 ◽  
Author(s):  
A L Newsome ◽  
J W McLean ◽  
M O Lively
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Immunoblot Analysis ◽  
Cross Reactivity ◽  
Amino Acid Sequences ◽  
Signal Peptidase ◽  
Amino Acid Residues ◽  
Protein Subunit ◽  
Chicken Oviduct ◽  
Dog Pancreas

Detergent-solubilized hen oviduct signal peptidase has been characterized previously as an apparent complex of a 19 kDa protein and a 23 kDa glycoprotein (GP23) [Baker & Lively (1987) Biochemistry 26, 8561-8567]. A cDNA clone encoding GP23 from a chicken oviduct lambda gt11 cDNA library has now been characterized. The cDNA encodes a protein of 180 amino acid residues with a single site for asparagine-linked glycosylation that has been directly identified by amino acid sequence analysis of a tryptic-digest peptide containing the glycosylated site. Immunoblot analysis reveals cross-reactivity with a dog pancreas protein. Comparison of the deduced amino acid sequence of GP23 with the 22/23 kDa glycoprotein of dog microsomal signal peptidase [Shelness, Kanwar & Blobel (1988) J. Biol. Chem. 263, 17063-17070], one of five proteins associated with this enzyme, reveals that the amino acid sequences are 90% identical. Thus the signal peptidase glycoprotein is as highly conserved as the sequences of cytochromes c and b from these same species and is likely to be found in a similar form in many, if not all, vertebrate species. The data also show conclusively that the dog and avian signal peptidases have at least one protein subunit in common.

scholarly journals Mouse IgG2a antibodies specific for the commensal Streptococcus mitis show stronger cross-reactivity with Streptococcus pneumoniae than IgG1 antibodies

2019 ◽  
Author(s):  
Sudhanshu Shekhar ◽  
Rabia Khan ◽  
Ata Ul Razzaq Khan ◽  
Fernanda Cristina Petersen
Keyword(s):  
Streptococcus Pneumoniae ◽  
Cross Reactivity ◽  
Pneumococcal Infections ◽  
Streptococcus Mitis ◽  
The Cross ◽  
Mouse Igg2a

AbstractHere we show that mouse IgG2a and IgG1 antibodies specific for the commensal Streptococcus mitis cross-react with the pathogen Streptococcus pneumoniae, although the cross-reactivity conferred by IgG2a is stronger than IgG1 antibodies. These findings may have implications for designing S. mitis-based vaccines against pneumococcal infections.

Human acidic ribosomal phosphoproteins P0, P1, and P2: analysis of cDNA clones, in vitro synthesis, and assembly

1987 ◽  
Vol 7 (11) ◽  
pp. 4065-4074
Author(s):  
B E Rich ◽  
J A Steitz
Keyword(s):  
Amino Acid ◽  
Cross Reactivity ◽  
Amino Acid Sequences ◽  
T7 Rna Polymerase ◽  
Cdna Clones ◽  
In Vitro Synthesis ◽  
E Coli ◽  
P Proteins ◽  
Carboxy Terminal

cDNA clones encoding three antigenically related human ribosomal phosphoproteins (P-proteins) P0, P1, and P2 were isolated and sequenced. P1 and P2 are analogous to Escherichia coli ribosomal protein L7/L12, and P0 is likely to be an analog of L10. The three proteins have a nearly identical carboxy-terminal 17-amino-acid sequence (KEESEESD(D/E)DMGFGLFD-COOH) that is the basis of their immunological cross-reactivity. The identities of the P1 and P2 cDNAs were confirmed by the strong similarities of their encoded amino acid sequences to published primary structures of the homologous rat, brine shrimp, and Saccharomyces cerevisiae proteins. The P0 cDNA was initially identified by translation of hybrid-selected mRNA and immunoprecipitation of the products. To demonstrate that the coding sequences are full length, the P0, P1, and P2 cDNAs were transcribed in vitro by bacteriophage T7 RNA polymerase and the resulting mRNAs were translated in vitro. The synthetic P0, P1, and P2 proteins were serologically and electrophoretically identical to P-proteins extracted from HeLa cells. These synthetic P-proteins were incorporated into 60S but not 40S ribosomes and also assembled into a complex similar to that described for E. coli L7/L12 and L10.

Proteomic analysis reveals developmentally expressed rice homologues of grass group II pollen allergens

2003 ◽  
Vol 30 (8) ◽  
pp. 843 ◽  
Author(s):  
Tursun Kerim ◽  
Nijat Imin ◽  
Jeremy J. Weinman ◽  
Barry G. Rolfe
Keyword(s):  
Amino Acid ◽  
Polyclonal Antibodies ◽  
Protein Sequences ◽  
Cross Reactivity ◽  
Amino Acid Sequences ◽  
Pollen Allergens ◽  
Specific Expression ◽  
Group I ◽  
Group Ii ◽  
Sequence Profiles

Three isoallergens of Ory s 2, homologues of grass group II pollen allergens, were identified from rice and characterised by proteome and immunochemical analyses. The N-terminal amino acid sequence profiles of three proteins on a 2-dimensional electrophoresis (2-DE) gel of rice pollen proteins matched 100% to the protein sequences encoded by three rice expressed sequence tags (ESTs). The deduced protein sequences from these ESTs share sequence identities of 41–43% with the protein sequences of the group II pollen allergens of different grasses, and sequence identity of 39% with the C-terminal portion of rice group I pollen allergens. Signal peptide sequences, which are similar to the leader peptides of other major pollen allergens, are also present in the deduced amino acid sequences. Polyclonal antibodies, produced in rabbits using Ory s 2 proteins purified by 2-DE, were used to investigate the developmental-stage- and tissue-specific expression of Ory s 2 by immunochemical analysis. Results of immunochemical experiments show that Ory s 2 proteins are expressed only at the late stage of pollen development and they do not have cross-reactivity with group II pollen allergens from some other common grasses.

scholarly journals Human acidic ribosomal phosphoproteins P0, P1, and P2: analysis of cDNA clones, in vitro synthesis, and assembly.

1987 ◽  
Vol 7 (11) ◽  
pp. 4065-4074 ◽  
Author(s):  
B E Rich ◽  
J A Steitz
Keyword(s):  
Amino Acid ◽  
Cross Reactivity ◽  
Amino Acid Sequences ◽  
T7 Rna Polymerase ◽  
Cdna Clones ◽  
In Vitro Synthesis ◽  
E Coli ◽  
P Proteins ◽  
Carboxy Terminal

cDNA clones encoding three antigenically related human ribosomal phosphoproteins (P-proteins) P0, P1, and P2 were isolated and sequenced. P1 and P2 are analogous to Escherichia coli ribosomal protein L7/L12, and P0 is likely to be an analog of L10. The three proteins have a nearly identical carboxy-terminal 17-amino-acid sequence (KEESEESD(D/E)DMGFGLFD-COOH) that is the basis of their immunological cross-reactivity. The identities of the P1 and P2 cDNAs were confirmed by the strong similarities of their encoded amino acid sequences to published primary structures of the homologous rat, brine shrimp, and Saccharomyces cerevisiae proteins. The P0 cDNA was initially identified by translation of hybrid-selected mRNA and immunoprecipitation of the products. To demonstrate that the coding sequences are full length, the P0, P1, and P2 cDNAs were transcribed in vitro by bacteriophage T7 RNA polymerase and the resulting mRNAs were translated in vitro. The synthetic P0, P1, and P2 proteins were serologically and electrophoretically identical to P-proteins extracted from HeLa cells. These synthetic P-proteins were incorporated into 60S but not 40S ribosomes and also assembled into a complex similar to that described for E. coli L7/L12 and L10.

A comparative study of repeated sequences in the SM50 gene of some sea urchins

Zygote ◽  
1999 ◽  
Vol 8 (S1) ◽  
pp. S75-S75
Author(s):  
Masayuki Goto ◽  
Masahiro Matsumoto ◽  
Takashi Kitajima ◽  
Akiya Hino
Keyword(s):  
Amino Acid ◽  
Sea Urchin ◽  
Sequence Data ◽  
Sea Urchins ◽  
Rabbit Antiserum ◽  
Pcr Primers ◽  
Amino Acid Sequences ◽  
Immunofluorescent Staining ◽  
Upstream Region ◽  
Amino Acid Region

Spicule matrix proteins of sea urchin embryo are the specific products of the micromere / primary mesenchyme cell (PMC) lineage, and are considered to be involved in spicule formation (Wilt, 1999). One of these proteins, SM50, has been described for three species: Strongylocentrotus purpuratus (SP), Lytechinus pictus (Lp) and Hemicentrotus pulcherrimus (Hp) (for references see Wilt, 1999). The nucleotide and amino acid sequences are well conserved in these species. SM50 proteins of these species have repetitive amino acid sequences in the carboxyl-terminal half of the proteins. Therefore, examination of SM50 sequences, especially the repetitive sequence region, in various species will help an understanding of the process of sea urchin ontogeny and evolution. In this study we tried to amplify, by PCR, the SM50 sequences of species for which no sequence data are reported.Total DNA was extracted from the sperm of sea urchins by standard procedures. The purified DNA was subjected to PCR to amplify the repetitive amino acid region and its upstream region. The primers were designed based on the highly conserved sequences in the reported SM50 as Consensus-Degenerate Hybrid Oligonucleotide Primers (Rose et al., 1997). The amplified products were gel-purified, and sequenced using ABI PRISM 310 Genetic Analyzer using PCR primers. The determined nucleotide sequences were translated into amino acid sequences and compared among species with a phylogenetic tree constructed by the neighbour-joining method. For indirect immunofluorescent staining, embryos were fixed with 70% methanol and reacted with rabbit antiserum against recombinant SM50 protein.

scholarly journals Conservation of the Conformation and Positive Charges of Hepatitis C Virus E2 Envelope Glycoprotein Hypervariable Region 1 Points to a Role in Cell Attachment

2001 ◽  
Vol 75 (12) ◽  
pp. 5703-5710 ◽  
Author(s):  
François Penin ◽  
Christophe Combet ◽  
Georgios Germanidis ◽  
Pierre-Olivier Frainais ◽  
Gilbert Deléage ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Amino Acid ◽  
Viral Entry ◽  
Envelope Glycoprotein ◽  
Cell Attachment ◽  
Hypervariable Region ◽  
Amino Acid Sequences ◽  
Specific Sequence ◽  
Amino Acid Region

ABSTRACT Chronic hepatitis C virus (HCV) infection is a major cause of liver disease. The HCV polyprotein contains a hypervariable region (HVR1) located at the N terminus of the second envelope glycoprotein E2. The strong variability of this 27-amino-acid region is due to its apparent tolerance of amino acid substitutions together with strong selection pressures exerted by anti-HCV immune responses. No specific function has so far been attributed to HVR1. However, its presence at the surface of the viral particle suggests that it might be involved in viral entry. This would imply that HVR1 is not randomly variable. We sequenced 460 HVR1 clones isolated at various times from six HCV-infected patients receiving alpha interferon therapy (which exerts strong pressure towards quasispecies genetic evolution) and analyzed their amino acid sequences together with those of 1,382 nonredundant HVR1 sequences collected from the EMBL database. We found that (i) despite strong amino acid sequence variability related to strong pressures towards change, the chemicophysical properties and conformation of HVR1 were highly conserved, and (ii) HVR1 is a globally basic stretch, with the basic residues located at specific sequence positions. This conservation of positively charged residues indicates that HVR1 is involved in interactions with negatively charged molecules such as lipids, proteins, or glycosaminoglycans (GAGs). As with many other viruses, possible interaction with GAGs probably plays a role in host cell recognition and attachment.

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