Specific activity and isotope abundances of strontium in purified strontium-82

2016 ◽  
Vol 31 (2) ◽  
pp. 458-463 ◽  
Author(s):  
J. M. Fitzsimmons ◽  
D. G. Medvedev ◽  
L. F. Mausner

A linear accelerator was used to irradiate a rubidium chloride target with protons to produce strontium-82 (Sr-82), and the Sr-82 was purified by ion exchange chromatography.

2021 ◽  
Vol 13 (2) ◽  
pp. 107-112
Author(s):  
C.F. Okechukwu ◽  
P.L. Shamsudeen ◽  
R.K. Bala ◽  
B.G. Kurfi ◽  
A.M. Abdulazeez

The most effective and acceptable therapy for snakebite victims is the immediate administration of antivenin which is limited by problems of hypersensitivity reactions in some individuals and its inability to resolve the local effects of the venom. The aim of this study was to isolate, partially purify and characterize phospholipase A2 from Naja Katiensis venom. Phospholipase A2 was partially purified via a two-step process: gel filtration on Sephadex G-75 and ion exchange chromatography using CM Sephadex, and subjected to SDS-PAGE analysis. From the results, the specific activity of the partially purified PLA2 decreased from 0.67μmol/min/mg in crude venom to 0.29μmol/min/mg after ion exchange chromatography with a yield of 5% and purification fold of 0.43. The optimum temperature of the purified PLA2 was found to be 35ºC and optimum p.H of 7. velocity studies for the determination of kinetic constants using L-a-lecithin as substrate revealed a Km  of 1.47mg/ml and Vmax  of 3.32μ moles/min/mg. The sodium dodecyl sulphate polyacrylamide gel electrophoresis of the purified PLA2 showed a distinct band with molecular weight estimated to be 14KDa. In conclusion, the present study shows that phospholipase A2 was isolated, purified and characterized. This may serve as a promising candidate for future development of a novel anti-venin drug.


1989 ◽  
Vol 263 (2) ◽  
pp. 477-483 ◽  
Author(s):  
J Deistung ◽  
R C Bray

A procedure is described for isolation of the pterin molybdenum cofactor, in the active molybdenum-containing state, starting from purified milk xanthine oxidase. The method depends on the use of anaerobic-glove-cabinet techniques and on working in aqueous solution, in the presence of 1 mM-Na2S2O4. SDS was used to denature the protein, followed by ion-exchange chromatography and gel filtration. The cofactor, obtained at concentrations up to 0.5-1.0 mM, was fully active in the nit-1 assay [Hawkes & Bray (1984) Biochem. J. 214, 481-493], with a specific activity of 22 nmol of NO2-/min per pg-atom of Mo (with 15% molybdate-dependence). The Mr, determined by gel filtration, was about 610, consistent with the structure proposed by Kramer, Johnson, Ribeiro, Millington & Rajagopalan [(1987) J. Biol. Chem. 262, 16357-16363]. At pH 5.9, under anaerobic conditions, the cofactor was stable for at least 300 h at 20-25 degrees C.


1989 ◽  
Vol 44 (9-10) ◽  
pp. 883-885 ◽  
Author(s):  
Kenji Matsui ◽  
Yasushi Shibata ◽  
Tadahiko Kajiwara ◽  
Akikazu Hatanaka

Abstract In cucumber cotyledons, both C6- and C9- aldehyde were formed via hydroperoxide (HPO) lyase activity. Because it has not been elucidated whether these activities are attributed to one enzyme which can cleave both 13-and 9-HPO or to two or more enzymes each of which specifically cleaves 13-or 9-HPO , an attempt to separate HPO lyase activity was done. Ion exchange chromatography separated this activity into two fractions, one of which specifically cleaved 13-hydroperoxylinoleic acid and the other specifically cleaved the 9-isomer. 13-HPO-specific activity was most active at pH 8.0 and 9-HPO-specific one was at pH 6.5. SH -reagents inhibited both the lyases but to different extents.


1980 ◽  
Vol 58 (21) ◽  
pp. 2280-2284 ◽  
Author(s):  
B. A. Maldonado ◽  
R. B. van Huystee

Medium that had supported the growth of a peanut cell suspension culture was found to be a rich source of peroxidase. Precipitation with acetone and ammonium sulfate, followed by a pH shift and ion exchange chromatography, led to the isolation of a single cationic peroxidase isozyme of high specific activity and high RZ of 2.91. The isolated peroxidase was shown to be a single peptide chain.


2000 ◽  
Vol 66 (1) ◽  
pp. 23-28 ◽  
Author(s):  
M. Beukes ◽  
G. Bierbaum ◽  
H.-G. Sahl ◽  
J. W. Hastings

ABSTRACT Streptococcus milleri NMSCC 061 was screened for antimicrobial substances and shown to produce a bacteriolytic cell wall hydrolase, termed millericin B. The enzyme was purified to homogeneity by a four-step purification procedure that consisted of ammonium sulfate precipitation followed by gel filtration, ultrafiltration, and ion-exchange chromatography. The yield following ion-exchange chromatography was 6.4%, with a greater-than-2,000-fold increase in specific activity. The molecular weight of the enzyme was 28,924 as determined by electrospray mass spectrometry. The amino acid sequences of both the N terminus of the enzyme (NH2 SENDFSLAMVSN) and an internal fragment which was generated by cyanogen bromide cleavage (NH2 SIQTNAPWGL) were determined by automated Edman degradation. Millericin B displayed a broad spectrum of activity against gram-positive bacteria but was not active againstBacillus subtilis W23 or Escherichia coli ATCC 486 or against the producer strain itself. N-Dinitrophenyl derivatization and hydrazine hydrolysis of free amino and free carboxyl groups liberated from peptidoglycan digested with millericin B followed by thin-layer chromatography showed millericin B to be an endopeptidase with multiple activities. It cleaves the stem peptide at the N terminus of glutamic acid as well as the N terminus of the last residue in the interpeptide cross-link of susceptible strains.


2016 ◽  
Vol 9 (1) ◽  
pp. 1 ◽  
Author(s):  
B. S. Fagbohunka ◽  
R. E. Okonji ◽  
Ayinla Zainab Adenike

Cellulase enzyme was purified and characterized from termite soldiers (Ametermes eveuncifer) using 70% ammonium sulphate precipitation, ion exchange chromatography and affinity chromatography. The enzyme isolated had a specific activity of 5.04 U/mg with a percentage yield of 11.7%. The enzyme showed maximum activity at 500C and pH 8. The enzyme was not inhibited by Ba2+ at a concentration of 1mM and Pb2+ at 10 mM concentration but was inhibited by other metal ions at 1 mM and 10 mM concentrations of their salts (NaCl, KCl, MnCl2, and NiCl2),


2020 ◽  
Vol 3 (2) ◽  
pp. 157
Author(s):  
Emmanuel Sina Akintimehin ◽  
Foluso Olutope Adetuyi ◽  
Kayode Olayele Karigidi ◽  
Raphael Emuebie Okonji ◽  
Clement Olomola Akinnubi

This research investigated the effects of postharvest storage on cyanide content and rhodanese isolated from bitter cassava (Manihot Utilissima) tubers. Cyanide content of freshly harvested sample, samples stored for 4 days and samples stored for 8 days were estimated by silver nitrate titration method. Rhodanese was purified using 80% ammonium sulphate precipitate and ion-exchange chromatography on CM-Sephadex C-25.Cyanide content from freshly harvested sample was 345.6 mg HCN/kg while 237.6 mg HCN/kg and 108 mg HCN/kg were obtained for samples stored for 4 days and samples stored for 8 days respectively. Specific activity of rhodanese from freshly harvested sample was 3.411 RU/mg while 5.92 RU/mg and 5.35 RU/mg were obtained for samples stored for 4 days and samples stored for 8 days respectively. The Km values of rhodanese for KCN were 3.18 mM, 2.40 mM, 0.25 mM for freshly harvested sample, samples stored for 4 days and samples stored for 8 days respectively. The optimum temperature from freshly harvested sample and sample stored for 4 days was 70 0C while samples stored for 8 days was 50 0C. An optimum pH of 4.0 was obtained from the 3 samples.Rhodanese play plausible role in cyanide reduction during the postharvest storage.


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