Faculty Opinions recommendation of Plasmodium falciparum ensures its amino acid supply with multiple acquisition pathways and redundant proteolytic enzyme systems.

2006 ◽  
Author(s):  
Paul Roepe
Keyword(s):  
Plasmodium Falciparum ◽  
Amino Acid ◽  
Proteolytic Enzyme ◽  
Enzyme Systems

scholarly journals Cysteine-Free Proteins in the Immunobiology of Arthropod-Borne Diseases

2010 ◽  
Vol 2010 ◽  
pp. 1-10 ◽  
Author(s):  
J. Santiago Mejia ◽  
Erik N. Arthun ◽  
Richard G. Titus
Keyword(s):  
Plasmodium Falciparum ◽  
Amino Acid ◽  
Distribution Patterns ◽  
Structural Features ◽  
Structure And Function ◽  
Cysteine Residues ◽  
Distribution Analysis ◽  
And Function ◽  
Abundance And Distribution ◽  
Host Parasite

One approach to identify epitopes that could be used in the design of vaccines to control several arthropod-borne diseases simultaneously is to look for common structural features in the secretome of the pathogens that cause them. Using a novel bioinformatics technique, cysteine-abundance and distribution analysis, we found that many different proteins secreted by several arthropod-borne pathogens, includingPlasmodium falciparum, Borrelia burgdorferi, and eight species of Proteobacteria, are devoid of cysteine residues. The identification of three cysteine-abundance and distribution patterns in several families of proteins secreted by pathogenic and nonpathogenic Proteobacteria, and not found when the amino acid analyzed was tryptophan, provides evidence of forces restricting the content of cysteine residues in microbial proteins during evolution. We discuss these findings in the context of protein structure and function, antigenicity and immunogenicity, and host-parasite relationships.

Structural and antigenic polymorphism of the 35- to 48-kilodalton merozoite surface antigen (MSA-2) of the malaria parasite Plasmodium falciparum

1991 ◽  
Vol 11 (2) ◽  
pp. 963-971
Author(s):  
B Fenton ◽  
J T Clark ◽  
C M Khan ◽  
J V Robinson ◽  
D Walliker ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Amino Acid ◽  
Surface Antigen ◽  
Dna Sequences ◽  
Amino Acid Sequences ◽  
Merozoite Surface Antigen ◽  
Parasite Plasmodium ◽  
Genes Encoding ◽  
Parasite Plasmodium Falciparum ◽  
Group B

Merozoite surface antigen MSA-2 of the human parasite Plasmodium falciparum is being considered for the development of a malaria vaccine. The antigen is polymorphic, and specific monoclonal antibodies differentiate five serological variants of MSA-2 among 25 parasite isolates. The variants are grouped into two major serogroups, A and B. Genes encoding two different variants from serogroup A have been sequenced, and their DNA together with deduced amino acid sequences were compared with sequences encoded by other alleles. The comparison shows that the serological classification reflects differences in DNA sequences and deduced primary structure of MSA-2 variants and serogroups. Thus, the overall homologies of DNA and amino acid sequences are over 95% among variants in the same serogroup. In contrast, similarities between the group A variants and a group B variant are only 70 and 64% for DNA and amino acid sequences, respectively. We propose that the MSA-2 protein is encoded by two highly divergent groups of alleles, with limited additional polymorphism displayed within each group.

Cloning of a Ca(2+)-ATPase gene of Plasmodium falciparum and comparison with vertebrate Ca(2+)-ATPases

1993 ◽  
Vol 104 (4) ◽  
pp. 1129-1136 ◽  
Author(s):  
M. Kimura ◽  
Y. Yamaguchi ◽  
S. Takada ◽  
K. Tanabe
Keyword(s):  
Plasmodium Falciparum ◽  
Plasma Membrane ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Phosphorylation Site ◽  
Genomic Libraries ◽  
Atpase Gene ◽  
Binding Regions ◽  
Cloned Gene ◽  
Falciparum Protein

A Ca(2+)-ATPase gene was cloned from the genomic libraries of Plasmodium falciparum. From the deduced amino acid sequence of the gene, a 139 kDa protein with a total of 1228 amino acids was predicted. Sequence of a partial cDNA clone of the gene identified two introns near the 3′-end at the regions identical to the regions assumed for the Ca(2+)-ATPase gene of P. yoelii, a rodent malaria species. As compared with a variety of Ca(2+)-ATPases, the P. falciparum Ca(2+)-ATPase had the highest amino acid sequence homology (78%) to the P. yoelii Ca(2+)-ATPase, moderate homology (45-50%) to vertebrate sarcoplasmic/endoplasmic reticulum Ca(2+)-ATPases (SERCAs), and lowest homology (20%) to a plasma membrane Ca(2+)-ATPase. The P. falciparum protein conserved sequences and residues that are important for the function and/or structure of the organellar type Ca(2+)-ATPase, such as high affinity Ca(2+)-binding sites, fluorescein isothiocyanate (FITC)-binding regions, and the phosphorylation site, but the protein did not contain calmodulin-binding regions that occur in the plasma membrane type Ca(2+)-ATPase. Thus we concluded the cloned gene was the organellar type Ca(2+)-ATPase of P. falciparum. In a region between the phosphorylation site and FITC-binding region, the P. falciparum protein was about 200 residues longer than the rabbit SERCA and lacked a sequence that binds to phospholamban, a protein that regulates the activity of the rabbit SERCA.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Genetic polymorphism of histidine rich protein 2 in Plasmodium falciparum isolates from different infection sources in Yunnan Province, China

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Ying Dong ◽  
Shuping Liu ◽  
Yan Deng ◽  
Yanchun Xu ◽  
Mengni Chen ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Amino Acid ◽  
Falciparum Malaria ◽  
Dna Sequences ◽  
Yunnan Province ◽  
Diversity Index ◽  
Peptide Sequence ◽  
Peptide Chain ◽  
Blood Samples

Abstract Background Failed diagnoses of some falciparum malaria cases by RDTs are constantly reported in recent years. Plasmodium falciparum histidine-rich protein 2 (pfhpr2) gene deficiency has been found to be the major reason of RDTs failure in many countries. This article analysed the deletion of pfhpr2 gene of falciparum malaria cases isolated in Yunnan Province, China. Methods Blood samples from falciparum malaria cases diagnosed in Yunnan Province were collected. Plasmodium genomic DNA was extracted and the pfhrp2 gene exon2 region was amplified via nested PCR. The haplotype of the DNA sequence, the nucleic acid diversity index (PI) and expected heterozygosity (He) were analyzed. Count PfHRP2 amino acid peptide sequence repeat and its times, and predict the properties of PfHRP2 peptide chain reaction to RDTs testing. Results A total of 306 blood samples were collected, 84.9% (259/306) from which pfhrp2 PCR amplification products (gene exon2) were obtained, while the remaining 47 samples were false amplification. The length of the 250 DNA sequences ranged from 345 - 927 bp, with 151 haplotypes, with PI and He values of 0.169 and 0.983, respectively. The length of the PfHRP2 peptide chain translated from 250 DNA sequences ranged from 115 to 309 aa. All peptide chains had more than an amino acid codon deletion. All 250 PfHRP2 strands ended with a type 12 amino acid repeat, 98.0% (245/250) started with a type 1 repetition and 2.0% (5/250) with a type 2 repetition. The detection rate for type 2 duplicates was 100% (250/250). Prediction of RDT sensitivity of PfHRP2 peptide chains based on type 2 and type 7 repeats showed that 9.60% (24/250), 50.0% (125/250), 13.20% (33/250) and 27.20.5% (68/250) of the 250 peptide chains were very sensitive, sensitive, borderline and non-sensitive, respectively. Conclusion The diversified polymorphism of the pfhrp2 gene deletion from different infection sources in the Yunnan province are extremely complex. The cause of the failure of pfhrp2 exon2 amplification is still to be investigated. The results of this study appeal to Yunnan Province for a timely evaluation of the effectiveness and applicability of RDTs in the diagnosis of malaria.

scholarly journals THE RELATION OF PROTEOLYTIC ENZYMES IN THE PNEUMONIC LUNG TO HYDROGEN ION CONCENTRATION. AN EXPLANATION OF RESOLUTION

1919 ◽  
Vol 30 (4) ◽  
pp. 379-388 ◽  
Author(s):  
Frederick T. Lord
Keyword(s):  
Amino Acid ◽  
Proteolytic Enzyme ◽  
Gradual Increase ◽  
Cellular Material ◽  
Hydrogen Ion ◽  
Ion Concentration ◽  
Acid Media ◽  
Hydrogen Ion Concentration ◽  
Ion Concentrations ◽  
Amino Acid Nitrogen

Evidence is given of the presence in the cellular material obtained from the pneumonic lung of a proteolytic enzyme digesting coagulated blood serum at hydrogen ion concentrations of 7.3 to 6.7 and inactive at higher; i.e., more acid concentrations. In addition, evidence is brought forward of the presence in the cellular material from the pneumonic lung of a proteolytic enzyme splitting peptone to amino-acid nitrogen. This enzyme is operative at hydrogen ion concentrations from 8.0 to 4.8, but most active at 6.3 or 5.2. These findings may be regarded as having a bearing on resolution in pneumonia. During the course of the disease a gradual increase in the hydrogen ion concentration of the exudate probably takes place. With the breaking down of cellular material an enzyme digesting protein (fibrin) in weakly alkaline and weakly acid media may be liberated. With a gradual increase in the hydrogen ion concentration of the pneumonic lung the action of this enzyme probably ceases. An enzyme capable of splitting peptone to amino-acid nitrogen is probably active during the proteolysis of the fibrin and further activated when the hydrogen ion concentration of the pneumonic lung is increased to within its range of optimum activity at a pH of 6.3 and 5.2. By this means it may be conceived that the exudate is dissolved and resolution takes place.

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