Cloning and functional expression of the gene encoding an inhibitor against Aspergillus flavus α-amylase, a novel seed lectin from Lablab purpureus (Dolichos lablab)

ABSTRACT The O antigen of serotype 1c differs from the unmodified O antigen of serotype Y by the addition of a disaccharide (two glucosyl groups) to the tetrasaccharide repeating unit. It was shown here that addition of the first glucosyl group is mediated by the previously characterized gtrI cluster, which is found within a cryptic prophage at the proA locus in the bacterial chromosome. Transposon mutagenesis was performed to disrupt the gene responsible for addition of the second glucosyl group, causing reversion to serotype 1a. Colony immunoblotting was used to identify the desired revertants, and subsequent sequencing, cloning, and functional expression successfully identified the gene encoding serotype 1c-specific O-antigen modification. This gene (designated gtrIC) was present as part of a three-gene cluster, similar to other S. flexneri glucosyltransferase genes. Relative to the other S. flexneri gtr clusters, the gtrIC cluster is more distantly related and appears to have arrived in S. flexneri from outside the species. Analysis of surrounding sequence suggests that the gtrIC cluster arrived via a novel bacteriophage that was subsequently rendered nonfunctional by a series of insertion events.

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EFFECT OF SOME PROCESSING METHODS ON NUTRIENT CONTENT AND ANTI-NUTRITIONAL FACTORS OF A VARIETY OF DOLICHOS LABLAB (LABLAB PURPUREUS L.) BEANS GROWN IN KENYA

10.37512/500 ◽

2019 ◽

Keyword(s):

Proximate Composition ◽

Crude Protein ◽

Nutrient Content ◽

Trypsin Inhibitor Activity ◽

Research Station ◽

Lablab Purpureus ◽

Processing Methods ◽

Nutritional Factors ◽

Dolichos Lablab ◽

Trypsin Inhibitory Activity

This study aimed to determine the effect of different processing methods on the proximate composition and anti-nutritional factors of Dolichos lablab beans (Lablab purpureus) of Kenya. The seeds of KAT/DL-2 variety,sourced from Kenya Agricultural Livestock and Research Organisation, Katumani Dryland Research Station were sorted, then subjected to different processing methods (soaking, cooking and germination). The samples were analysed for proximate composition, tannins, phytates and trypsin inhibitory activity. The results showed a significant increase (2.0%) in crude protein content for germinated lablab beans while carbohydrates content was high in cooked samples. The variety KAT/DL-2 had high levels of phytates; 723.6 mg/100g and tannins 330.3mg/100g and trypsin inhibitor activity 1.3mg/100g. Cooking achieved the highest reduction of anti-nutrients with 88% reduction in TIU. The results revealed that the anti-nutrients in lablab beans can be reduced using different methods of processing. However, there is need to investigate the effect of combined methods on the nutrients and anti-nutrients.

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The identification, cloning and functional expression of the gene encoding orotidine 5'-monophosphate (OMP) decarboxylase fromPlasmodium falciparum

Annals of Tropical Medicine and Parasitology ◽

10.1179/000349802125001230 ◽

2002 ◽

Vol 96 (5) ◽

pp. 469-476 ◽

Cited By ~ 4

Author(s):

R. I. Menz ◽

O. Cinquin ◽

R. I. Christopherson

Keyword(s):

Functional Expression ◽

Gene Encoding

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Cloning and functional expression of a gene encoding a vacuolar-type proton-translocating pyrophosphatase from Trypanosoma cruzi

Biochemical Journal ◽

10.1042/0264-6021:3510281 ◽

2000 ◽

Vol 351 (1) ◽

pp. 281 ◽

Cited By ~ 24

Author(s):

Janet E. HILL ◽

David A. SCOTT ◽

Shuhong LUO ◽

Roberto DOCAMPO

Keyword(s):

Trypanosoma Cruzi ◽

Functional Expression ◽

Gene Encoding

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Inhibition of Growth of Aspergillus flavus and Fungal α-Amylases by a Lectin-Like Protein from Lablab purpureus

Molecular Plant-Microbe Interactions ◽

10.1094/mpmi.2001.14.8.955 ◽

2001 ◽

Vol 14 (8) ◽

pp. 955-961 ◽

Cited By ~ 43

Author(s):

A. M. Fakhoury ◽

C. P. Woloshuk

Keyword(s):

Aspergillus Flavus ◽

Insect Pests ◽

Hyphal Growth ◽

Aflatoxin Production ◽

Lablab Purpureus ◽

Ear Rot ◽

Amylase Inhibitor ◽

Isolation And Characterization ◽

Novel Variant ◽

Rot Disease

Aspergillus flavus is a fungal pathogen of maize causing an important ear rot disease when plants are exposed to drought and heat stress. Associated with the disease is the production of aflatoxins, which are a series of structurally related mycotoxins known to be carcinogenic. Previous research has suggested that the α-amylase of A. flavus promotes aflatoxin production in the endosperm of infected maize kernels. We report here the isolation and characterization of a 36-kDa α-amylase inhibitor from Lablab purpureus (AILP). AILP inhibited the α-amylases from several fungi but had little effect on those from animal and plant sources. The protein inhibited conidial germination and hyphal growth of A. flavus. The amino acid sequence indicated that AILP is similar to lectin members of a lectin-arcelin-α-amylase inhibitor family described in common bean and shown to be a component of plant resistance to insect pests. AILP also agglutinated papain-treated red blood cells from human and rabbit. These data indicate that AILP represents a novel variant in the lectin-arcelin-α-amylase inhibitor family of proteins having lectin-like and α-amylase inhibitory activity.

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Isolation and functional expression of human COQ2, a gene encoding a polyprenyl transferase involved in the synthesis of CoQ

Biochemical Journal ◽

10.1042/bj20040261 ◽

2004 ◽

Vol 382 (2) ◽

pp. 519-526 ◽

Cited By ~ 81

Author(s):

Margareta FORSGREN ◽

Anneli ATTERSAND ◽

Staffan LAKE ◽

Jacob GRÜNLER ◽

Ewa SWIEZEWSKA ◽

...

Keyword(s):

Biosynthetic Pathway ◽

Functional Expression ◽

Human Muscle ◽

Null Mutant ◽

Human Homologue ◽

Gene Encoding ◽

Reading Frame ◽

Human Enzyme ◽

Liver Cdna Library ◽

Mutant Cells

The COQ2 gene in Saccharomyces cerevisiae encodes a Coq2 (p-hydroxybenzoate:polyprenyl transferase), which is required in the biosynthetic pathway of CoQ (ubiquinone). This enzyme catalyses the prenylation of p-hydroxybenzoate with an all-trans polyprenyl group. We have isolated cDNA which we believe encodes the human homologue of COQ2 from a human muscle and liver cDNA library. The clone contained an open reading frame of length 1263 bp, which encodes a polypeptide that has sequence homology with the Coq2 homologues in yeast, bacteria and mammals. The human COQ2 gene, when expressed in yeast Coq2 null mutant cells, rescued the growth of this yeast strain in the absence of a non-fermentable carbon source and restored CoQ biosynthesis. However, the rate of CoQ biosynthesis in the rescued cells was lower when compared with that in cells rescued with the yeast COQ2 gene. CoQ formed when cells were incubated with labelled decaprenyl pyrophosphate and nonaprenyl pyrophosphate, showing that the human enzyme is active and that it participates in the biosynthesis of CoQ.

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