scholarly journals Biochemical characterization and essentiality ofPlasmodiumfumarate hydratase

2017 ◽  
Author(s):  
Vijay Jayaraman ◽  
Arpitha Suryavanshi ◽  
Pavithra Kalale ◽  
Jyothirmai Kunala ◽  
Hemalatha Balaram
Keyword(s):  
Biochemical Characterization ◽  
Tricarboxylic Acid Cycle ◽  
Fumarate Hydratase ◽  
Class I ◽  
Iron Sulfur Cluster ◽  
Mercaptosuccinic Acid ◽  
Nanomolar Range ◽  
Strain Dependent ◽  
Selection Of

ABSTRACTPlasmodium falciparum(Pf), the causative agent of malaria has an iron-sulfur cluster-containing class I fumarate hydratase (FH) that catalyzes the interconversion of fumarate to malate, a well-known reaction in the tricarboxylic acid cycle. In humans, the same reaction is catalyzed by class II FH that has no sequence or structural homology with the class I enzyme. Fumarate, generated in large quantities in the parasite as a byproduct of AMP synthesis is converted to malate by the action of FH, and subsequently used in the generation of the key metabolites oxaloacetate, aspartate and pyruvate. Here we report on the kinetic characterization of purified recombinant PfFH, functional complementation offhdeficiency inEscherichia coliand mitochondrial localization in the parasite. The substrate analog, mercaptosuccinic acid was found to be a potent inhibitor of PfFH with a Kivalue in the nanomolar range. Knockout of thefhgene was not possible inP. bergheiwhen drug-selection of the transfectants was performed in BALB/c mice while the gene was amenable to knockout when C57BL/6 mice were used as host, thereby indicating mouse-strain dependent essentiality of thefhgene to the parasite.

scholarly journals SELECTION OF PEACH GENOTYPES FOR BIOCHEMICAL FRUIT QUALITY CHARACTERIZATION

2017 ◽  
Vol 39 (4) ◽  
Author(s):  
KELI CRISTINA FABIANE ◽  
AMÉRICO WAGNER JÚNIOR ◽  
JULIANO ZANELA ◽  
CRISTIANO HOSSEL ◽  
IDEMIR CITADIN
Keyword(s):  
Functional Foods ◽  
Phenylalanine Ammonia Lyase ◽  
Reducing Sugars ◽  
Prunus Persica ◽  
Biochemical Characterization ◽  
Total Proteins ◽  
Breeding Programs ◽  
Organoleptic Characteristics ◽  
Selection Of

ABSTRACT Peach is much appreciated by consumers and its popularity is mainly related with organoleptic characteristics. However, with emergence of concepts of functional foods (health promoters), there is high interest to study and to quantify the biochemical components of fruits. The aim of this work was to perform the biochemical characterization of peach genotypes, evaluating the genetic diversity and selecting those with desirable biochemical qualities for use as parents in future breeding programs. The experiment was carried out at the Laboratory of Plant Physiology - UTFPR - Campus of Dois Vizinhos, PR (Brazil), with fruits from 26 and 29 peach genotypes (Prunus persica) in the 2009/2010 and 2010/2011 crop years, respectively. The experimental design was entirely randomized, considering each genotype as treatment, using four replicates and four fruits per plot. Total and reducing sugars, total proteins, amino acids, total phenols, anthocyanins, flavonoids and phenylalanine ammonia-lyase enzyme activity (PAL) in fruits were evaluated. According to the results of two crop years, ‘Cascata 967’, ‘Conserva 985’, ‘Kampai’, ‘Tropic Snow’ and ‘Cascata 1055’ were selected as those with the highest levels of these compounds.

scholarly journals Biochemical Characterization of Streptococcus pneumoniae Penicillin-Binding Protein 2b and Its Implication in β-Lactam Resistance

2004 ◽  
Vol 48 (5) ◽  
pp. 1848-1855 ◽  
Author(s):  
Estelle Pagliero ◽  
Laurent Chesnel ◽  
Julie Hopkins ◽  
Jacques Croizé ◽  
Otto Dideberg ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Biochemical Characterization ◽  
Protein A ◽  
Strain Analysis ◽  
Penicillin G ◽  
Penicillin Binding Protein ◽  
Class B ◽  
Selection Of

ABSTRACT Extensive use of β-lactam antibiotics has led to the selection of pathogenic streptococci resistant to β-lactams due to modifications of the penicillin-binding proteins (PBPs). PBP2b from Streptococcus pneumoniae is a monofunctional (class B) high-molecular-weight PBP catalyzing the transpeptidation between adjacent stem peptides of peptidoglycan. The transpeptidase domain of PBP2b isolated from seven clinical resistant (CR) strains contains 7 to 44 amino acid changes over the sequence of PBP2b from the R6 β-lactam-sensitive strain. We show that the extracellular soluble domains of recombinant PBP2b proteins (PBP2b*) originating from these CR strains have an in vitro affinity for penicillin G that is reduced by up to 99% from that of the R6 strain. The Thr446Ala mutation is always observed in CR strains and is close to the key conserved motif (S443SN). The Thr446Ala mutation in R6 PBP2b* displays a 60% reduction in penicillin G affinity in vitro compared to that for the wild-type protein. A recombinant R6 strain expressing the R6 PBP2b Thr446Ala mutation is twofold less sensitive to piperacillin than the parental S. pneumoniae strain. Analysis of the Thr446Ala mutation in the context of the PBP2b CR sequences revealed that its influence depends upon the presence of other unidentified mutations.

Biochemical characterization of a P43,12 complex: Comparison with human and murine class I molecules

1985 ◽  
Vol 22 (6) ◽  
pp. 695-703 ◽  
Author(s):  
Yuri Bushkin ◽  
Michael J. Chorney ◽  
Edson Diamante ◽  
Caryl Lane ◽  
Shu Man Fu ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Class I

scholarly journals ANTIFUNGAL ACTIVITY OF ACTINOBACTERIA WITH A POTENTIAL TO INHIBIT RICE BLAST FUNGUS MAGNAPORTHE ORYZAE (ANAMORPH PYRICULARIA ORYZAE)

2021 ◽  
pp. 121-125
Author(s):  
THILAGAM R ◽  
BALAGURUNATHAN R ◽  
SANGEETHA M ◽  
HEMALATHA N
Keyword(s):  
Secondary Metabolites ◽  
Magnaporthe Oryzae ◽  
Rice Blast ◽  
Biochemical Characterization ◽  
Fungal Growth ◽  
Pathogenic Fungi ◽  
Antifungal Compound ◽  
Layer Chromatography ◽  
Selection Of

Objective: The aims of the present study were to screen the actinobacteria with high potential ability to produce secondary metabolites that have inhibitory activity against plant pathogenic fungi, Magnaporthe oryzae. Production of secondary metabolites was analysis by thin-layer chromatography and bioautography assay. Methods: Screening and selection of potential Streptomyces sp. morphological, cultural, physiological, and biochemical characterization of the screened isolate was carried out. Antifungal compound was confirmed by bioautography assay. Results: Bioautography method use in this study was found to be antifungal fraction from the crude extract. Antifungal secondary metabolites can be readily located on the plates by observing clear zones where active compounds inhibit fungal growth. Conclusion: The bioautography assay shows that this isolates can produce antifungal compound. Therefore, this isolate proves to be a promising microbe which can be further studied for its applications a biocontrol agent against rice blast fungi.

scholarly journals The class I-b molecule Qa-1 forms heterodimers with H-2Ld and a novel 50-kD glycoprotein encoded centromeric to I-E beta.

1995 ◽  
Vol 181 (2) ◽  
pp. 657-668 ◽  
Author(s):  
P R Wolf ◽  
R G Cook
Keyword(s):  
Cell Surface ◽  
Biochemical Characterization ◽  
Noncovalent Interactions ◽  
Protein Product ◽  
Class I ◽  
Mouse Strains ◽  
Histocompatibility Complex ◽  
Beta 2 Microglobulin

Recent biochemical characterization of the T23-encoded Qa-1 molecule revealed an additional higher molecular mass species of 50 kD coprecipitated with the 48-kD Qa-1 molecule in H-2b and H-2d mouse strains. We now demonstrate that the 50-kD protein coprecipitated with Qa-1 is the class I-a antigen Ld in all H-2Ld-positive mouse strains examined. Furthers analyses of a panel of recombinants revealed that the 50-kD protein coprecipitated with Qa-1 in H-2b haplotype mouse strains is encoded or controlled by a gene centromeric to major histocompatibility complex class II I-E beta. We have designated this gene and corresponding protein product as Qsm, Qa-1 structure modifier. Both Ld and Qsm can interact with Qa-1 to form cell surface-expressed heterodimers in vivo. These Qa-1 heterodimers are not expressed in H-2k haplotype cells. The Qa-1/Ld and Qa-1/Qsm heterodimers are associated by noncovalent interactions and occur only between fully processed proteins. In addition, we show that the Qsm-encoded protein can form heterodimers with Ld as well, and that the Ld molecules participating in these interactions with Qa-1 and Qsm may be devoid of beta 2-microglobulin and/or peptide. These data represent the first demonstration that class I molecules can be expressed as heterodimers (Qa-1/Ld) on the cell surface, and map a gene (Qsm) that may potentially encode a novel class I molecule, or another protein, that associates with both Qa-1 and Ld. These interactions may enable increased levels of Qa-1 to reach the cell surface and may subsequently influence T cell recognition of Qa-1 and/or Ld molecules.

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