INHERITANCE OF FREE BETA-AMYLASE IN BARLEY

1964 ◽  
Vol 44 (6) ◽  
pp. 550-554 ◽  
Author(s):  
V. M. Bendelow

The proportion of beta-amylase activity that is free, or water-soluble, is useful in screening barley hybrid lines for potential malting quality. It was found to be at one of two distinct levels in 56 barley varieties. The levels, designated high and low, are independent of year and location. Tests were made on F2 and backcross populations derived from varieties differing in level of free beta-amylase. The results indicated that the level is dependent on the action of a single gene-pair with incomplete dominance. The level of free enzyme activity is apparently inherited independently of total beta-amylase activity.

Genetics ◽  
1998 ◽  
Vol 150 (1) ◽  
pp. 383-391 ◽  
Author(s):  
Hoang V Tang ◽  
Ruying Chang ◽  
Daryl R Pring

Abstract Defective nuclear-cytoplasmic interactions leading to aberrant microgametogenesis in sorghum carrying the IS1112C male-sterile cytoplasm occur very late in pollen maturation. Amelioration of this condition, the restoration of pollen viability, involves a novel two-gene gametophytic system, wherein genes designated Rf3 and Rf4 are required for viability of individual gametes. Rf3 is tightly linked to, or represents, a single gene that regulates a transcript processing activity that cleaves transcriptsof orf107, a chimeric mitochondrial open reading frame specific to IS1112C. The mitochondrial gene urf 209 is also subject to nucleus-specific enhanced transcript processing, 5′ to the gene, conferred by a single dominant gene designated Mmt1. Examinations of transcript patterns in F2 and two backcross populations indicated cosegregation of the augmented orf107 and urf209 processing activities in IS1112C. Several sorghum lines that do not restore fertility or confer orf107 transcript processing do exhibit urf209 transcript processing, indicating that the activities are distinguishable. We conclude that the nuclear gene(s) conferring enhanced orf107 and urf209 processing activities are tightly linked in IS1112C. Alternatively, the similarity in apparent regulatory action of the genes may indicate allelic differences wherein the IS1112C Rf3 allele may differ from alleles of maintainer lines by the capability to regulate both orf107 and urf209 processing activities.


1980 ◽  
Vol 87 (1) ◽  
pp. 65-71 ◽  
Author(s):  
MASAYOSHI KUMEGAWA ◽  
NORIHIKO MAEDA ◽  
TOSHIHIKO YAJIMA ◽  
TAISHIN TAKUMA ◽  
EIKO IKEDA ◽  
...  

The effects of cortisol (10 μg/g body weight) and l-thyroxine (T4; 0·2 μg/g body weight) on the activity of parotid gland amylase in young rats were investigated. Administration of cortisol or T4 for 5 consecutive days from day 5 after birth caused the precocious appearance of amylase, T4 having almost twice the effect of cortisol. Cortisol and T4 did not have synergistic effects. In thyroidectomized-adrenalectomized rats, T4 increased amylase activity but cortisol did not. The increase in enzyme activity after day 20 was much less in rats thyroidectomized on day 10 than in rats adrenalectomized on day 10. These results suggest that T4 has a direct effect on the early increase of amylase activity (days 15–25) and that the action of glucocorticoid requires the presence of endogenous thyroid hormones. The hormone-induced level of amylase in intact rats was less than that of normal adult rats. Forced weaning of intact rats resulted in a further increase in amylase activity, suggesting that further amylase accumulation (after day 25) may be due to dietary factors.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Imen Lahmar ◽  
Hanen El Abed ◽  
Bassem Khemakhem ◽  
Hafedh Belghith ◽  
Ferjani Ben Abdallah ◽  
...  

A continuous research is attempted to fulfil the highest industrial demands of natural amylases presenting special properties. Newα-amylases extracted from stems and leaves ofPergularia tomentosa, which is widespread and growing spontaneously in Tunisia, were studied by the means of their activities optimization and purification. Some similarities were recorded for the two identified enzymes: (i) the highest amylase activity showed a promoted thermal stability at 50°C; (ii) the starch substrate at 1% enhanced the enzyme activity; (iii) the twoα-amylases seem to be calcium-independent; (iv) Zn2+, Cu2+, and Ag2+were considered as important inhibitors of the enzyme activity. Following the increased gradient of elution on Mono Q-Sepharose column, an increase in the specific activity of 11.82-fold and 10.92-fold was recorded, respectively, for leaves and stems with the presence of different peaks on the purification profiles.Pergulariaamylases activities were stable and compatible with the tested commercial detergents. The combination of plant amylase and detergent allowed us to enhance the wash performance with an increase of 35.24 and 42.56%, respectively, for stems and leaves amylases. Characterized amylases were reported to have a promoted potential for their implication notably in detergent industry as well as biotechnological sector.


1997 ◽  
Vol 129 (4) ◽  
pp. 371-378 ◽  
Author(s):  
J. E. FLINTHAM ◽  
W. J. ANGUS ◽  
M. D. GALE

The Rht-B1b, Rht-D1b and Rht-B1c alleles for reduced height in wheat (the Norin 10 and Tom Thumb dwarfing genes previously known as Rht1, Rht2 and Rht3) were exploited in combinations to generate a near-continuous range of plant heights, from 53 cm to 123 cm, amongst near-isogenic homozygotes and F1 hybrids. Pleiotropic yield effects of Rht genes were measured in both homozygous (intravarietal) and heterozygous (intervarietal) genetic backgrounds. Heterosis due to overdominance of Rht genes was detected among intravarietal hybrids. The effects of heterozygosity at other genetic loci (mean dominance) were determined, independently of Rht effects, from comparisons between intravarietal and intervarietal F1 hybrids.Genotypes of intermediate plant heights gave maximum yields, in agreement with other trials of the homozygous lines, so that heterosis (hybrid exceeding best parent) for Rht yield effects was observed in crosses between tall and dwarf isogenic pairs. This heterosis combined additively with increased mean weight per grain in intervarietal crosses, generating the highest overall grain yields in hybrids with semi-dwarf stature in heterozygous genetic backgrounds. The Rht-B1c allele showed single-gene overdominance for grain yield, also the production of alpha-amylase in ripening grains of Maris Huntsman was effectively inhibited in the Rht-B1a/c intravarietal hybrid. The Rht-B1c allele thus offers advantages for both grain yield and grain quality in the heterozygous condition and should be considered as an alternative to the conventional semi-dwarfing genes Rht-B1b and Rht-D1b for F1 varieties in environments conductive to preharvest sprouting.


2015 ◽  
Vol 2015 ◽  
pp. 1-9 ◽  
Author(s):  
Kantrao Saware ◽  
Ravindra Mahadappa Aurade ◽  
P. D. Kamala Jayanthi ◽  
Venkataraman Abbaraju

Amylase is one of the important digestive enzymes involved in hydrolysis of starch. In this paper, we describe a novel approach to study the interaction of amylase enzyme with gold nanoparticles (AuNPs) and silver nanoparticles (AgNPs) and checked its catalytic function. AuNPs are synthesized using citrate reduction method and AgNPs were synthesized using biological route employing Ficus benghalensis and Ficus religiosa leaf extract as a reducing and stabilizing agent to reduce silver nitrate to silver atoms. A modulatory effect of nanoparticles on amylase activity was observed. Gold nanoparticles are excellent biocompatible surfaces for the immobilization of enzymes. Immobilized amylase showed 1- to 2-fold increase of activity compared to free enzyme. The biocatalytic activity of amylase in the bioconjugate was marginally enhanced relative to the free enzyme in solution. The bioconjugate material also showed significantly enhanced pH and temperature stability. The results indicate that the present study paves way for the modulator degradation of starch by the enzyme with AuNPs and biogenic AgNPs, which is a promising application in the medical and food industry.


2006 ◽  
Vol 395 (3) ◽  
pp. 641-652 ◽  
Author(s):  
Richard K. Hughes ◽  
Eric J. Belfield ◽  
Mylrajan Muthusamay ◽  
Anuja Khan ◽  
Arthur Rowe ◽  
...  

We describe the detailed biochemical characterization of CYP74C3 (cytochrome P450 subfamily 74C3), a recombinant plant cytochrome P450 enzyme with HPL (hydroperoxide lyase) activity from Medicago truncatula (barrel medic). Steady-state kinetic parameters, substrate and product specificities, RZ (Reinheitszahl or purity index), molar absorption coefficient, haem content, and new ligands for an HPL are reported. We show on the basis of gel filtration, sedimentation velocity (sedimentation coefficient distribution) and sedimentation equilibrium (molecular mass) analyses that CYP74C3 has low enzyme activity as a detergent-free, water-soluble, monomer. The enzyme activity can be completely restored by re-activation with detergent micelles, but not detergent monomers. Corresponding changes in the spin state equilibrium, and probably co-ordination of the haem iron, are novel for cytochrome P450 enzymes and suggest that detergent micelles have a subtle effect on protein conformation, rather than substrate presentation, which is sufficient to improve substrate binding and catalytic-centre activity by an order of magnitude. The kcat/Km of up to 1.6×108 M−1·s−1 is among the highest recorded, which is remarkable for an enzyme whose reaction mechanism involves the scission of a C–C bond. We carried out both kinetic and biophysical studies to demonstrate that this effect is a result of the formation of a complex between a protein monomer and a single detergent micelle. Association with a detergent micelle rather than oligomeric state represents a new mechanism of activation for membrane-associated cytochrome P450 enzymes. Highly concentrated and monodispersed samples of detergent-free CYP74C3 protein may be well suited for the purposes of crystallization and structural resolution of the first plant cytochrome P450 enzyme.


PLoS ONE ◽  
2013 ◽  
Vol 8 (9) ◽  
pp. e72875 ◽  
Author(s):  
Xue Gong ◽  
Sharon Westcott ◽  
Xiao-Qi Zhang ◽  
Guijun Yan ◽  
Reg Lance ◽  
...  

1993 ◽  
Vol 296 (3) ◽  
pp. 685-691 ◽  
Author(s):  
K S Siddiqui ◽  
T Loviny-Anderton ◽  
M Rangarajan ◽  
B S Hartley

To try to lower the pH optimum, the carboxy groups of Arthrobacter D-xylose isomerase were coupled to glycinamide using a water-soluble carbodi-imide. In conditions that substituted all of the 59 carboxy groups in the denatured monomer, a maximum of 30 groups/monomer reacted in the native enzyme, whether in presence or absence of ligands, and the enzyme remained fully active and tetrameric throughout the coupling reaction. Purification by f.p.l.c. ion-exchange chromatography gave broad symmetrical peaks with increased pI, suggesting that the modified enzymes are essentially homogeneous. However, they are less stable than native enzyme in 8 M urea or on heating (‘melting points’ of 59 degrees versus 73 degrees C for the apoenzymes and 67 degrees versus 81.5 degrees C for the Mg(2+)-enzymes). Kinetic studies of the D-fructose isomerase activity at 30 degrees C showed that the glycinamidylated enzyme had unaltered activation constant for Mg2+, and Km was also similar to that of the native enzyme at pH 7.3, but increased rapidly at higher pH rather than remaining constant. Vmax. was constant from pH 6.2 to 8.0, suggesting a reduced pKa for His-219, which controls Vmax. in the native enzyme (normally 6.0). Three mutants were constructed by protein engineering with a view to reducing the pH optimum of enzyme activity. Two of these, Glu140→Lys and Asp189→Lys, could be detected in crude extracts of Escherichia coli by SDS/PAGE, but could not be purified, whereas mutant Trp136→Glu was produced as a tetramer in amounts similar to the wild-type enzyme. However, it did not show any enzyme activity and was less stable in 0-9 M urea gradient PAGE.


2020 ◽  
Vol 22 (1) ◽  
Author(s):  
INDAH KHOIRUN NISA ◽  
Prabaningtyas Sitoresmi ◽  
BETTY LUKIATI ◽  
RINA TRITURANI SAPTAWATI ◽  
ACHMAD RODIANSYAH

Abstract. Nisa IK, Prabaningtyas S, Lukiati B, Saptawati RT, Rodiansyah A. 2021. The potential of amylase enzyme activity against bacteria isolated from several lakes in East Java, Indonesia. Biodiversitas 21: 42-49. Indonesia is one country that has water resources having an abundance of microbial diversity, but not explored massively. This study aims to measure the amylase activity quantitatively from 53 amylolytic bacterial isolates from Ranu Pani, Ranu Regulo, Ranu Grati, and Ngebel Lake; also it identifies the isolate with the highest amylase enzyme activity. The amylase enzyme activity test calculates with DNS (Dinitrosalycylic acid) method, molecular identification of the highest bacterial isolate is based on the 16S rRNA gene. Its relationship is determined through the phylogenetic tree with the Neighbor-Joining (NJ) method. The results showed that the fifty-three bacterial isolates have amylase activity about 0.000-0.016 units/mL. The KN bacterial isolate from Ranu Ngebel was the highest amylase activity, producing enzyme around 0.016 units/mL, while isolate G20 from Ranu Grati was the lowest, reaching about 0.0001 Unit/mL. Based on the morphological and molecular identification, the KN bacterial isolate is classified as the Bacillus cereus group with 99.4-100% sequence similarity, closely related to Bacillus paramycoides (NR 157734.1).


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