scholarly journals Toxic peptides and genes encoding toxin γ of the Brazilian scorpions Tityus bahiensis and Tityus stigmurus

1996 ◽  
Vol 313 (3) ◽  
pp. 753-760 ◽  
Author(s):  
Baltazar BECERRIL ◽  
Miguel CORONA ◽  
Fredy I. V. CORONAS ◽  
Fernando ZAMUDIO ◽  
Emma S. CALDERONARANDA ◽  
...  
Keyword(s):  
Chemical Characterization ◽  
Large Degree ◽  
Cross Reactivity ◽  
Terminal Sequence ◽  
Cdna Sequences ◽  
Genes Encoding ◽  
Tityus Serrulatus ◽  
Toxic Peptides ◽  
Degree Of Similarity

Seven toxic peptides from the venom of Tityus bahiensis and Tityus stigmurus were isolated and sequenced, five of them to completion. The most abundant peptide from each of these two species of scorpion was 95% identical with that of toxin γ from the venom of Tityus serrulatus. They were consequently named γ-b and γ-st respectively. The genes encoding these new γ-like peptides were cloned and sequenced by utilizing oligonucleotides synthesized according to known cDNA sequences of toxin γ, and amplified by PCR on templates of DNA purified from both T. bahiensis and T. stigmurus. They contain an intron of approx. 470 bp. Possible mechanisms of processing and expressing these peptides are discussed, in view of the fact that glycine is the first residue of the N-terminal sequence of T. stigmurus, whereas lysine is the residue at position 1 of toxin γ from T. serrulatus and T. bahiensis. In addition, chemical characterization of the less abundant toxic peptides showed the presence of at least four distinct families of peptides in all three species of the genus Tityus studied. There is a large degree of similarity among peptides from different venoms of the same family. By using specific horse and rabbit antisera, the venoms of T. bahiensis, T. serrulatus and T. stigmurus were compared. They showed an extended degree of cross-reactivity. Thus these three species of scorpion have similar toxic components, the genes of which are similarly organized, processed and expressed.

scholarly journals Characterization of the Duffy-Binding-Like Domain of Plasmodium falciparum Blood-Stage Antigen 332

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Sandra Nilsson ◽  
Kirsten Moll ◽  
Davide Angeletti ◽  
Letusa Albrecht ◽  
Inari Kursula ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Immunofluorescence Microscopy ◽  
Homology Model ◽  
Cross Reactivity ◽  
Blood Stage ◽  
Conserved Domain ◽  
Erythrocyte Binding ◽  
High Degree ◽  
Degree Of Similarity

Studies on Pf332, a major Plasmodium falciparum blood-stage antigen, have largely been hampered by the cross-reactive nature of antibodies generated against the molecule due to its high content of repeats, which are present in other malaria antigens. We previously reported the identification of a conserved domain in Pf332 with a high degree of similarity to the Duffy-binding-like (DBL) domains of the erythrocyte-binding-like (EBL) family. We here describe that antibodies towards Pf332-DBL are induced after repeated exposure to P. falciparum and that they are acquired early in life in areas of intense malaria transmission. Furthermore, a homology model of Pf332-DBL was found to be similar to the structure of the EBL-DBLs. Despite their similarities, antibodies towards Pf332-DBL did not display any cross-reactivity with EBL-proteins as demonstrated by immunofluorescence microscopy, Western blotting, and peptide microarray. Thus the DBL domain is an attractive region to use in further studies on the giant Pf332 molecule.

scholarly journals Chemical Characterization of a Non-Covalently Linked Peptide from Plakalbumin

1969 ◽  
Vol 22 (1) ◽  
pp. 239 ◽  
Author(s):  
R Sleigh ◽  
R Hosken MB Smith ◽  
EOP Thompson
Keyword(s):  
Chemical Characterization ◽  
Protein Component ◽  
Terminal Portion ◽  
Terminal Sequence ◽  
Covalently Linked

A 33�residue peptide isolated from plakalbumin by dissociation with urea at pH 3 is shown to be derived from the a-terminal portion of ovalbumin. The yield of proline obtained on hydrazinolysis was the same as that from ovalbumin, whereas proline was not liberated from the protein component. The N�terminal sequence of this peptide was determined by the Edman degradative procedure to be Ser. V al.Ser .Glu.Glu.Phe.Arg.Ala.Asp.

scholarly journals Purification and chemical characterization of the major toxins from the venom of the Brazilian scorpion Tityus serrulatus Lutz and Mello

1981 ◽  
Vol 46 (4) ◽  
pp. 195-205 ◽  
Author(s):  
Lourival Domingos Possani ◽  
Brian M. Martin ◽  
Javier Mochca-Morales ◽  
Ib Svendsen
Keyword(s):  
Chemical Characterization ◽  
Tityus Serrulatus

scholarly journals The Biosynthetic Pathway for Myxol-2′ Fucoside (Myxoxanthophyll) in the Cyanobacterium Synechococcus sp. Strain PCC 7002

2009 ◽  
Vol 191 (10) ◽  
pp. 3292-3300 ◽  
Author(s):  
Joel E. Graham ◽  
Donald A. Bryant
Keyword(s):  
Biosynthetic Pathway ◽  
Chemical Characterization ◽  
Open Reading Frame ◽  
Biotechnological Applications ◽  
Reading Frame ◽  
Genes Encoding ◽  
Synechococcus Sp ◽  
Related Compounds ◽  
Β Carotene

ABSTRACT Synechococcus sp. strain PCC 7002 produces a variety of carotenoids, which comprise predominantly dicylic β-carotene and two dicyclic xanthophylls, zeaxanthin and synechoxanthin. However, this cyanobacterium also produces a monocyclic myxoxanthophyll, which was identified as myxol-2′ fucoside. Compared to the carotenoid glycosides produced by diverse microorganisms, cyanobacterial myxoxanthophyll and closely related compounds are unusual because they are glycosylated on the 2′-OH rather than on the 1′-OH position of the ψ end of the molecule. In this study, the genes encoding two enzymes that modify the ψ end of myxoxanthophyll in Synechococcus sp. strain PCC 7002 were identified. Mutational and biochemical studies showed that open reading frame SynPCC7002_A2032, renamed cruF, encodes a 1′-hydroxylase and that open reading frame SynPCC7002_A2031, renamed cruG, encodes a 2′-O-glycosyltransferase. The enzymatic activity of CruF was verified by chemical characterization of the carotenoid products synthesized when cruF was expressed in a lycopene-producing strain of Escherichia coli. Database searches showed that homologs of cruF and cruG occur in the genomes of all sequenced cyanobacterial strains that are known to produce myxol or the acylic xanthophyll oscillaxanthin. The genomes of many other bacteria that produce hydroxylated carotenoids but do not contain crtC homologs also contain cruF orthologs. Based upon observable intermediates, a complete biosynthetic pathway for myxoxanthophyll is proposed. This study expands the suite of enzymes available for metabolic engineering of carotenoid biosynthetic pathways for biotechnological applications.

Antigenic and structural relationships within group 19 Streptococcuspneumoniae: chemical characterization of the specific capsular polysaccharides of types 19B and 19C

1992 ◽  
Vol 70 (1) ◽  
pp. 218-232 ◽  
Author(s):  
Linda M. Beynon ◽  
James C. Richards ◽  
Malcolm B. Perry ◽  
Peter J. Kniskern
Keyword(s):  
Capsular Polysaccharide ◽  
Chemical Characterization ◽  
Structural Similarity ◽  
Cross Reactivity ◽  
Resonance Spectroscopy ◽  
Capsular Polysaccharides ◽  
Phosphate Diester ◽  
Structural Relationships ◽  
Nuclear Overhauser

The specific capsular polysaccharides of Streptococcuspneumoniae types 19B and 19C (American types 58 and 59) were investigated by a combination of 1H, 13C, and 31P nuclear magnetic resonance spectroscopy and analytical methods based on mass spectrometry. The two polysaccharides were found to be high molecular weight polymers composed of L-rhamnose, 2-amino-2-deoxy-D-mannose, D-ribose, D-glucose, and phosphate. Homo- and heteronuclear chemical shift correlation techniques and nuclear Overhauser enhancement experiments led to the unambiguous assignment of the 1H and 13C resonances from the glycose residues and established their sequence within repeating oligosaccharide units. The oligosaccharide units are polymerized through phosphate diester linkages.[Formula: see text]Both polysaccharides share a common hexasaccharide structural unit and they differ only in the degree of substitution at the branched 2-acetamido-2-deoxy-β-D-mannopyranosyl residue: the 19C polysaccharide is O-6 linked by β-D-glucopyranosyl end groups to form a heptasaccharide repeating unit, while the 19B polysaccharide is unsubstituted at that position. The serologic cross-reactivity between S. pneumoniae serotypes 19B and 19C can now be related to the structural similarity of the antigenic capsular polysaccharides. Keywords: Streptococcuspneumoniae, capsular polysaccharide, immuno chemistry.

Olfactory and Chemical Characterization of Indoor Air-Towards a Psychophysical Model for Air Quality

1981 ◽  
Author(s):  
Birgitta Berglund ◽  
Ulf Berglund ◽  
Thomas Lindvall ◽  
Helene Nicander-Bredberg
Keyword(s):  
Air Quality ◽  
Indoor Air ◽  
Chemical Characterization
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