Development of Isocitric Lyase Activity in Germinating Prickly Sida Seed

Weed Science ◽  
1976 ◽  
Vol 24 (3) ◽  
pp. 298-301 ◽  
Author(s):  
Bonnie J. Reger ◽  
E. Wayne Smith

Maximum activity of isocitric lyase (EC 4.1.3.1) was reached at 24 hr incubation of afterripened (nondormant) prickly sida (Sida spinosaL.) seed. Enzyme activity declined gradually with incubation times in excess of 24 hr. Actinomycin D (Act D) at 5 μg/ml had essentially no effect on 24-hr germination but inhibited development of isocitric lyase activity 83%. Cycloheximide (CH) at 10 μg/ml inhibited 24-hr germination of punctured seed only 7% but inhibited development of isocitric lyase activity 76%. Seed incubated in water 12 hr before being transferred to Act D at 5 μg/ml for an additional 12 hr did not escape sensitivity to the antibiotic. Isocitric lyase activity was inhibited when assayed at 24 hr total incubation. In the reverse experiment, seed incubated in Act D 12 hr before being transferred to water, isocitric lyase activity at 24 hr was not affected. Apparently prickly sida seed lacked a performed mRNA for isocitric lyase and transcription and translation of the mRNA occurred shortly after initiation of radicle protrusion (~8 hr).

1972 ◽  
Vol 50 (3) ◽  
pp. 299-304 ◽  
Author(s):  
Vijendra K. Singh ◽  
S. C. Sung

DNA-dependent RNA polymerase, which was isolated from beef brain nuclei, was stimulated by Mn2+ and Mg2+. The polymerase was about four times as active with Mn2+ as with Mg2+ but both of these divalent cations were required for maximum activity. KCl stimulated the enzyme activity with an optimum concentration around 0.2 M. The stimulation by KCl was much more pronounced in the presence of Mn2+ or Mn2+ plus Mg24 than in the presence of Mg2+ alone. Spermidine and spermine also stimulated the RNA polymerase activity and this stimulation was much greater in the presence of Mn2+ than in the presence of Mg2+ or both together. With Mn2+ plus Mg2+, spermidine had little or no stimulatory effect when heat-denatured DNA served as template, whereas with Mn2+ alone, spermidine markedly stimulated the enzyme in the presence of either native or heat-denatured DNA. The effect of spermidine was different with Mg2+ alone. The enzyme was inhibited as much as 75% by actinomycin D and almost completely by α-amanitin but not by rifampicin. Yeast RNA inhibited the enzyme activity considerably while spermidine appeared to overcome and prevent this inhibition of RNA polymerase.


Author(s):  
Soad A. Abdelgalil ◽  
Ahmad R. Attia ◽  
Reyed M. Reyed ◽  
Nadia A. Soliman

Abstract Background Due to the multitude industrial applications of ligninolytic enzymes, their demands are increasing. Partial purification and intensive characterization of contemporary highly acidic laccase enzyme produced by an Egyptian local isolate designated Alcaligenes faecalis NYSO were studied in the present investigation. Results Alcaligenes faecalis NYSO laccase has been partially purified and intensively biochemically characterized. It was noticed that 40–60% ammonium sulfate saturation showed maximum activity. A protein band with an apparent molecular mass of ~ 50 kDa related to NYSO laccase was identified through SDS-PAGE and zymography. The partially purified enzyme exhibited maximum activity at 55 °C and pH suboptimal (2.5–5.0). Remarkable activation for enzyme activity was recognized after 10-min exposure to temperatures (T) 50, 60, and 70 °C; time elongation caused inactivation, where ~ 50% of activity was lost after a 7-h exposure to 60 °C. Some metal ions Cu2+, Zn2+, Co2+, Ni2+, Mn2+, Cd2+, Cr2+, and Mg2+ caused strong stimulation for enzyme activity, but Fe2+ and Hg2+ reduced the activity. One millimolar of chelating agents [ethylenediamine tetraacetic acid (EDTA), sodium citrate, and sodium oxalate] caused strong activation for enzyme activity. Sodium dodecyl sulfate (SDS), cysteine-HCl, dithiothreitol (DTT), β-mercaptoethanol, thioglycolic acid, and sodium azide caused strong inhibition for NYSO laccase activity even at low concentration. One millimolar of urea, imidazole, kojic acid, phenylmethylsulfonyl fluoride (PMSF), H2O2, and Triton X-100 caused activation. The partially purified NYSO laccase had decolorization activity towards different dyes such as congo red, crystal violet, methylene blue, fast green, basic fuchsin, bromophenol blue, malachite green, bromocresol purple eriochrome black T, and Coomassie Brilliant Blue R-250 with various degree of degradation. Also, it had a vast range of substrate specificity including lignin, but with high affinity towards p-anisidine. Conclusion The promising properties of the newly studied laccase enzyme from Alcaligenes faecalis NYSO strain would support several industries such as textile, food, and paper and open the possibility for commercial use in water treatment. It will also open the door to new applications due to its ligninolytic properties in the near future.


1980 ◽  
Vol 186 (3) ◽  
pp. 755-761 ◽  
Author(s):  
A A B Badawy ◽  
B M Snape ◽  
M Evans

1. Acute ethanol administration causes a biphasic change in rat liver tyrosine aminotransferase activity. 2. The initial decrease is significant with a 200 mg/kg dose of ethanol, is prevented by adrenoceptor-blocking agnets and by reserpine, but not by inhibitors of ethanol metabolism, and exhibits many of the characteristics of the inhibition caused by noradrenaline. 3. The subsequent enhancement of the enzyme activity by ethanol is not associated with stabilization of the enzyme, but is sensitive to actinomycin D and cycloheximide. 4. It is suggested that the initial decrease in aminotransferase activity is caused by the release of catecholamines, whereas the subsequent enhancement may be related to the release of glucocorticoids.


cftm ◽  
2021 ◽  
Author(s):  
Josh T. Copes ◽  
Donnie K. Miller ◽  
Rakesh K. Godara ◽  
James L. Griffin

Parasitology ◽  
1973 ◽  
Vol 67 (2) ◽  
pp. 197-204 ◽  
Author(s):  
Madan M. Goil

Biochemical studies on the non-specific phosphomonoesterases have demonstrated the presence of acid phosphomonoesterase with maximum activity at pH 4·0 in Gastrodiscus aegyptiacus (enzyme I) and at pH 4·5 in the case of Fasdolopsis buski (enzyme II). The Km for ρ-nitrophenyl phosphate hydrolysis was 0·66 mM for enzyme I and 1·1 mM for enzyme II. Different concentrations of fluoride, arsenate, tartrate, tartaric acid, cysteine and copper brought about inhibition of both enzymes and magnesium, iodoaeetate, iodoacetamide and EDTA had no influence on either enzyme activity. Cobalt activated both enzymes while zinc inhibited enzyme I and strongly stimulated enzyme II.


1968 ◽  
Vol 46 (9) ◽  
pp. 1121-1129 ◽  
Author(s):  
Peter M. K. Ip ◽  
Shan-Ching Sung

Two DNases have been isolated and separated from Novikoff ascites hepatoma by ammonium sulfate fractionation and have been further purified by chromatography on ion-exchange columns of DEAE types.The partially purified acid DNase is free of any measurable RNase activity, while the partially purified alkaline DNase preparation still exhibits RNase activity.The alkaline DNase requires sulfhydryl compounds for maximum activity, whereas the acid DNase does not. Both DNases require Mg2+ ions for maximum activity. EDTA strongly inhibits the alkaline DNase activity and the inhibition can be reversed by the addition of Mg2+ ions. On the other hand, EDTA activates the acid DNase either in the presence or in the absence of Mg2+.Sarkomycin inhibits the alkaline DNase but does not inhibit the acid DNase. Actinomycin D and heparin inhibit both DNase activities.The products of the alkaline DNase digestion consist of four deoxymononucleotides as well as higher oligonucleotides, all terminating in 5′-phosphate. The alkaline DNase seems to exhibit an endonucleolytic mode of attack in the early stage of hydrolysis with a subsequent exonucleolytic action. However, the possibility of contamination by an unknown exonuclease cannot be ruled out. On the other hand, the products of the acid DNase digestion consist mainly of oligonucleotides with average chain length larger than 8 units all terminating in 3′-phosphate. No mononucleotides can be detected. This suggests that the acid DNase is a typical endonuclease and possesses no detectable exonuclease activity.The acid DNase preferentially attacks linkages of the type dPupGp, whereas the preferential linkage(s) for the alkaline DNase has not been established.


1976 ◽  
Vol 231 (5) ◽  
pp. 1557-1561 ◽  
Author(s):  
DV Maudsley ◽  
J Leif ◽  
Y Kobayashi

Ornithine decarboxylase in the small intestine of starved rats was stimulated 3- to 10-fold by refeeding or administration of insulin. A peak is observed 3-5 h following treatment after which the enzyme activity rapidly declines. The rise in ornithine decarboxylase is reduced by actinomycin D or cycloheximide. The increase in enzyme activity occurs mainly in the duodenum and jejunum with less than a twofold change being observed in the ileum. A small (twofold) increase in S-adenosylmethionine decarboxylase activity in the small intestine was observed after food, but there was no change in diamine oxidase activity. Whereas pentagastrin and metiamide administration markedly stimulated histidine decarbosylase in the gastric mucosa, no consistent effect of these agents on ornithine decarboxylase in the small intestine was observed. The similarities and differences between histidine decarboxylase and ornithine decarboxylase are discussed.


Weed Science ◽  
1977 ◽  
Vol 25 (3) ◽  
pp. 233-237 ◽  
Author(s):  
R.J. Newton ◽  
G.H. Egley

Dormant (fresh) and nondormant (afterripened) prickly sida (Sida spinosaL.) seeds were extracted and bioassayed for both inhibitory and promotory growth regulators. Both dormant and nondormant prickly sida seeds contained water-soluble inhibitors, but these inhibitor levels in nondormant seeds did not change after 8 hr of incubation. A basic inhibitor was present in dormant seeds, but not in nondormant seeds. Exogenous growth regulators stimulated germination of dormant seeds only when a portion of the seed coat was removed. Promoter levels in nonincubated, dormant and nondormant seeds were similar, but there were increases in promoter levels in nondormant seeds after 8 hr of incubation. However, it was not determined whether the promoter increases were a cause or a result of germination.


1989 ◽  
Vol 16 (2) ◽  
pp. 87-91 ◽  
Author(s):  
T. C. Mueller ◽  
P. A. Banks

Abstract RE-40885 (5-(methylamino)-2-phenyl-4-3-(trifluoromethyl phenyl)-3(2H)-furanone), a newly developed herbicide with soil and foliar activity, was evaluated for weed control in peanuts (Arachis hypogea L.). RE-40885 applied to the soil or foliage provided excellent Florida beggarweed (Desmodium tortuosum (Sw.) DC.) and prickly sida (Sida spinosa L.) control at rates of 0.56 to 1.12 kg ai/ha. Sequential applications of RE-40885 were needed to achieve > 90% sicklepod (Cassia obtusifolia L.) control. Texas panicum (Panicum texanum Buckl.) was not adequately controlled by any of the RE-40885 treatments evaluated. Peanuts were not injured by RE-40885 at any of the evaluated rates or application times. The combination of RE-40885 and 2,4-DB applied early postemergence improved sicklepod control 8 weeks after planting when compared to either RE-40885 or 2,4-DB applied alone. The combination of R E-40885 and alachlor applied at peanut emergence improved morningglory (Ipomoea spp.) control 8 weeks after planting and increased peanut yield when compared to either applied alone. All treatments containing RE-40885 resulted in peanut yields that were significantly better than nontreated weedy control plots.


2019 ◽  
Vol 6 (1) ◽  
pp. 57-61 ◽  
Author(s):  
Amika Ahmed Manzum ◽  
Md Arafat Al Mamun

Cellualse is one of the most important enzymes used in textile, detergent, paper, food and feed industries. Therefore, a study was undertaken to isolate Bacillus bacteria having the potential to produce cellulase from soil samples. 24 soil samples were analyzed and 54 presumptive Bacillus isolates were isolated after heating the soil samples at 80°C for 10 min. Among them 45 isolates showed enzyme activity ranging from 0.003 to 0.17 U/ml in test tubes containing 5 ml medium composed of (g/L) glucose 0.5 gm, peptone 0.75 gm, FeSO4 0.01 gm, KH2PO4 0.5 gm, and MgSO4 0.5 gm at 120 rpm, 37° C and pH 7. Among them 1RW, 2WS, 3YR, 4WT, 6 RR, and 9SS showed 0.17, 0.15, 0.14, 0.15, 0.147 and 0.14U/ml enzyme activities, respectively. Production of cellulase by these isolates was further scaled up to shake culture containing 50 ml medium similar to that used in test tube culture. Among the isolates 1 RW showed the maximum activity. This 1 RW was identified by API kit and showed that 59 % belongs to Bacillus licheniformis strain (51% confirmation) or Bacillus subtilis (31% confirmation). Further gene analysis is required to confirm the species. The genetic improvement study will make the isolate a good source of cellulase.


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