Molecular cloning and characterization of the polypeptide backbone of Schistosoma mansoni circulating cathodic antigen.
One of the candidate schistosome antigens for the development of a circulating antigen detection diagnostic assay is the circulating cathodic antigen (CCA). Detection of CCA in urine provides a non-invasive assay with high sensitivity. Previously we reported that CCA is secreted in patients' urine as a small molecular weight material which is probably of a proteinaceous nature. In an attempt to further characterize the secreted component of CCA, we used a monoclonal antibody (MAb) reactive with urine-CCA to isolate an adult worm cDNA clone (SmN3-1) that encodes the polypeptide backbone of CCA. The sequence, gene organization and expression of SmN3-1 were analyzed. The 1.6 kb nucleotide and 347 amino acid sequences of SmN3-1 showed no significant homology to any published sequence. The size and antigenic properties of the expression product of SmN3-1 in Escherichia coli greatly resembled the CCA molecule excreted in urine, suggesting that the latter is primarily composed of the protein element of CCA.
US Naval Medical Research Unit No.3, Cairo, Egypt. boushrah@namru3.navy.mil
H H
HH
Abdeen
A F
AF
Attallah
M M
MM
Mansour
R A
RA
Harrison
D000595:Amino Acid Sequence; D000818:Animals; D000947:Antigens, Helminth / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics* / Q000652:urine; D001483:Base Sequence; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000235:genetics; D018509:DNA, Helminth / Q000235:genetics; D017125:Genes, Protozoan; D006023:Glycoproteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics* / Q000652:urine; D015801:Helminth Proteins / Q000096:biosynthesis / Q000737:chemistry* / Q000235:genetics* / Q000652:urine; D006801:Humans; D008969:Molecular Sequence Data; D010455:Peptides; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis / Q000737:chemistry; D012550:Schistosoma mansoni / Q000235:genetics / Q000254:growth & development / Q000276:immunology*; D012555:Schistosomiasis mansoni / Q000469:parasitology; D017422:Sequence Analysis, DNA
D000947:Antigens, Helminth; C091532:CCA protein, Schistosoma mansoni; D018076:DNA, Complementary; D018509:DNA, Helminth; D006023:Glycoproteins; D015801:Helminth Proteins; D010455:Peptides; D011993:Recombinant Fusion Proteins