Cloning and characterization of the merozoite surface antigen 1 gene of Plasmodium berghei.

Abstract

Abstract. Merozoite surface antigen 1 (MSA1) is a promising candidate for vaccine development against malaria parasites. Here, we report the complete nucleotide sequence of the gene encoding the precursor to this major surface antigen of Plasmodium berghei strain ANKA using cDNA library screening and polymerase chain reaction techniques. A single open reading frame of 5,376 basepairs encoding a protein with a calculated molecular mass of 197 kD was defined. The protein contains a putative signal peptide of 19 amino acids, a membrane anchor sequence of 18 residues, and shows two epidermal growth factor-like domains rich in Cys residues at the C-terminus. There are four repeat sequences of oligopeptides in the molecule: tetrapeptide (Ser-Thr-Thr-Thr), tripeptide (Pro-Thr-Pro and Pro-Ala-Ala), and dipeptide (Ser-Gly). Furthermore, three nine-residue stretches of a motif (Ala-Ser-Asn-Pro-Gly-Ala-Ser-Ala-Ser) are located near each other. All of these repeat sequences are unexceptionally located in the variable regions when compared with other MSA1 molecules. The molecule displays 79% overall identity to the analogous antigen of P. yoelii yoelii strain YM, 70% to that of P. chabaudi chabaudi strain AS, and 38% to that of P. falciparum strain Wellcome.

Isolation and Characterization of the MSP1 Genes from Plasmodium malariae and Plasmodium ovale

“…34,35 The Pm and Po MSP1s also harbor imperfect tandem peptide repeats, ranging in size from 2 to 19 amino acids, which are present in two regions of low interspecies similarity flanked between ICBs 7, 9, and 11. An additional repeat domain is observed further downstream for the Po MSP1 in a third non-conserved region between ICBs 11 and 13 ( Figure 1 ).…”

MOLECULAR ANALYSIS OF PBMSP-1 GENE IN ERYTHROCYTE OF MICE INFECTED WITH Plasmodium berghei

“…PCR analysis by using primer PbMSP-1 detected DNA band sized 426 bp. This band is fit with PbMSP-1 gene band reported by Zhong et al (1999) by using cDNA λgt11 that corresponds with block 3 of conserved region and block 4 of variable region from P. falciparum. Sequence with size of 426 bp that encode MSP-1 from P. berghei species have similarity with MSP-1 sequence from other rodent Plasmodium species, also it has similarity with Plasmodium that infects human (Del Portillo et al, 1991;Toebe et al, 1997).…”

“…Large band size shows that extracted DNA is in form of DNA total that contain various gene. Concentration and quality of DNA extraction results are determined by spectrophotometer with absorbance of A260/A280 (Zhong et al, 1999). Qualified DNA was stored and used in next PCR for observation on PbMSP-1 gene.…”

A Protective Glycosylphosphatidylinositol-Anchored Membrane Protein ofPlasmodium yoeliiTrophozoites and Merozoites Contains Two Epidermal Growth Factor-Like Domains

“…For example, the EGF-like domains of P. falciparum MSP-1 and MSP-4 are conserved in the homologous antigens of P. yoelii, P. chabaudi, and P. berghei (5,9,30,38,46). By crosshybridization with pypAg-2 probes, we have isolated genomic clones encoding related P. falciparum antigens.…”