[Cloning and sequencing of the genes coding for the histidine-rich protein II of Plasmodium falciparum].
OBJECTIVE
To compare and analyze the homology of genes encoding histidine-rich proteinII (HRPII) of different Plasmodium falciparum isolates.


METHODS
Using PCR technique, the complete genes coding for HRPII of P. falciparum isolates FCC1/HN and VN isolates were amplified. PCR products were digested by HindIII/BamHI and cloned into plasmid pUC19. The recombinant plasmid HRPII/pUC19 was screened and identified by PCR and restriction analysis. The cloned HRPII genes were sequenced by Sanger's method.


RESULTS
HRPII genes of FCC1/HN and VN isolates were successfully amplified and cloned into pUC19. DNA sequencing showed that the coding length of HRPII gene was 1,020 bp without introns in FCC1/HN and VN isolates, however, there were ten points mutations between them. FCC1/HN isolate exhibited 98.8%, 92.2% and 98.7% homology in amino acids with isolates VN, IMTM22, and Itg2, respectively. Though the numbers of repeat sequences were different in four isolates, they had the same hydrophobic leader sequence and a single putative glycosylation site. The secondary structure analysis showed that the main antigenic determinants of four isolates were located on 5' end non-repeat region (amino acids 1-60).


CONCLUSIONS
FCC1/HN isolate was highly homologous in the coding region of HRPII with VN, IMTM22, and Itg2 isolate. Four isolates exhibited similar structural characteristics and antigenic determinants in HRPII.
Fang
J
J
Department of Parasitology, Sun Yat-sen University of Medical Sciences, Guangzhou 510089.
Yu
X
X
Luo
S
S
Xu
J
J
D000595:Amino Acid Sequence; D000818:Animals; D000953:Antigens, Protozoan / Q000737:chemistry / Q000235:genetics; D000954:Antigens, Surface / Q000235:genetics; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D016054:DNA, Protozoan / Q000032:analysis; D017780:Malaria Vaccines / Q000627:therapeutic use; D016778:Malaria, Falciparum / Q000517:prevention & control; D008969:Molecular Sequence Data; D010963:Plasmodium falciparum / Q000235:genetics* / Q000378:metabolism; D011506:Proteins / Q000235:genetics* / Q000627:therapeutic use; D012091:Repetitive Sequences, Nucleic Acid / Q000235:genetics; D016415:Sequence Alignment; D000099053:Histidine-Rich Glycoprotein
D000953:Antigens, Protozoan; D000954:Antigens, Surface; D016054:DNA, Protozoan; D017780:Malaria Vaccines; D011506:Proteins; D000099053:Histidine-Rich Glycoprotein