Partial purification and characterization of prolyl hydroxylase from the free-living nematode Panagrellus silusiae

1978 ◽  
Vol 56 (2) ◽  
pp. 159-165 ◽  
Author(s):  
J. R. A. Leushner ◽  
J. Pasternak

Prolyl hydroxylase was isolated from the free-living nematode Panagrellus silusiae by ammonium sulfate precipitation and calcium phosphate gel ion exchange from Triton X-100 treated homogenates. The enzyme preparation was highly purified but not to homogeneity as judged by agarose gel filtration and sodium dodecyl sulfate (SDS) – polyacrylamide gel electrophoresis. Gel filtration indicated that the molecular weight of the enzyme approximated 285 000. Analysis by SDS–acrylamide electrophoresis revealed subunits of ~67 000. Complete enzymic activity required α-ketoglutarate, Fe2+, ascorbate, catalase, atmospheric oxygen, and dithiothreitol. This activity was dramatically inhibited by α, α-dipyridyl, phenanthroline, and polyproline II. The purified enzyme preparation synthesized 50 to 100 μg hydroxyproline per milligram chick protocollagen per hour at 30 °C with an estimated Km for the substrate of 80 μg. Thus, a purified prolyl hydroxylase from a simple invertebrate possesses many of the properties of the prolyl hydroxylases of various vertebrates.

1983 ◽  
Vol 29 (11) ◽  
pp. 1526-1531 ◽  
Author(s):  
Susan E. Jensen ◽  
Donald W. S. Westlake ◽  
Saul Wolfe

Epimerase activity, which converts isopenicillin N to penicillin N, has been partially purified from cell-free extracts of Streptomyces clavuligerus. No stimulating cofactors of this activity were found, and neither EDTA nor anaerobic incubation caused significant inhibition of activity. Although pyridoxal phosphate did not stimulate epimerase activity, the presence of this cofactor was necessary for the stabilization of enzymic activity during the purification process. Epimerase activity was purified 35.5-fold by a combination of salt precipitation, gel filtration, and ion exchange chromatography. Gel filtration indicated that the epimerase has a molecular weight of 60 000 and sodium dodecyl sulphate – polyacrylamide gel electrophoresis of the 35.5-fold purified epimerase showed a major protein band running near that location. Pyridoxal phosphate antagonists did not uniformly inhibit epimerase activity, but the inhibitory effect of hydroxylamine could be partially reversed by pyridoxal phosphate.


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.


1979 ◽  
Vol 57 (4) ◽  
pp. 330-335 ◽  
Author(s):  
J. Scott Noble ◽  
J. Pasternak

Polysomal RNA was isolated from the free-living nematode Panagrellus silusiae. Passage of this RNA through a cellulose column resulted in the fractionation of the input RNA into poly(A)− RNA (ca. 97.5% of the total) and poly(A)+ RNA (ca. 2.5% of the total). RNase digestion, followed by polyacrylamide gel electrophoresis, revealed that the poly(A)+ RNA contained poly(A) tracts that ranged from 75 to 104 nucleotides in length with a mean value of about 90 residues. There was no evidence of poly(A) sequences in the poly(A)− RNA fraction. Poly(A)+ RNA gave a 25- to 50-fold stimulation (over background) of amino acid incorporation in the wheat germ cell-free protein-synthesizing system. At least 26 proteins were evident after electrophoresis in cylindrical sodium dodecyl sulfate – polyacrylamide gels. Poly(A)− RNA was capable of stimulating protein synthesis in vitro with about five discrete proteins being produced. In summary, the properties of mRNA from a simple organism such as P. silusiae are very similar to those of more complex eukaryotes.


1984 ◽  
Vol 224 (1) ◽  
pp. 171-179 ◽  
Author(s):  
I R Cottingham ◽  
A L Moore

The external NADH dehydrogenase has been purified from Arum maculatum (cuckoo-pint) mitochondria by phosphate washing, extraction with deoxycholate, ion-exchange and gel-filtration chromatography. Sodium dodecyl sulphate/polyacrylamide-gel electrophoresis shows, when the gel is silver-stained, that the purified enzyme contains two major bands of Mr 78 000 and 65 000 and a minor one of Mr about 76 000. It is not possible at present to determine which of these, or which combination, constitutes the dehydrogenase. The enzyme contains non-covalently bound FAD and a small amount of FMN. Since the conditions of purification lead to considerable loss of flavin and possibly iron-sulphur centres, it is not possible to decide with certainty whether the enzyme is a flavo- or ferroflavo-protein. The enzyme has been distinguished from the other NADH dehydrogenases on the basis of its substrate specificity, its capability of reducing electron acceptors such as ubiquinone-1 and 2,6-dichlorophenol-indophenol and its sensitivity towards Ca2+, EGTA and dicoumarol.


1982 ◽  
Vol 207 (1) ◽  
pp. 133-138 ◽  
Author(s):  
M G Battelli ◽  
E Lorenzoni

A new GSSG-dependent thiol:disulphide oxidoreductase was extensively purified from rat liver cytosol. The enzymic protein shows molecular weight 40 000 as determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, and 43 000 as determined by thin-layer gel filtration on Bio-Gel P-100. The pI is 8.1. This enzyme converts rat liver xanthine dehydrogenase into an oxidase, in the presence of oxidized glutathione. Other disulphide compounds are either inactive or far less active than oxidized glutathione in the enzymic oxidation of rat liver xanthine dehydrogenase. The enzyme also catalyses the reduction of the disulphide bond of ricin and acts as a thioltransferase and as a GSH:insulin transhydrogenase. The enzymic activity was measured in various organs of newborn and adult rats.


1984 ◽  
Vol 247 (4) ◽  
pp. G385-G393 ◽  
Author(s):  
I. M. Roberts ◽  
R. K. Montgomery ◽  
M. C. Carey

We have partially purified lingual lipase from the serous glands of rat tongue. With a combination of Triton X-100 extraction or Triton X-114 phase-separation techniques, Bio-Bead SM-2 treatment, dialysis, and gel filtration on Sephadex G-200 or Sephacryl S-300, we obtained a sparingly soluble lipid-free protein demonstrating hydrolytic activity against triglycerides and negligible phospholipase or cholesteryl esterase activities. Compared with homogenate, specific activities of the enzyme were enriched 3- to 5-fold prior to gel filtration and 10-fold after gel filtration. Analysis by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and gel filtration under denaturing conditions (6 M guanidine X HCl or 0.1% sodium dodecyl sulfate) revealed one major glycoprotein band with Mr approximately 50,000. Gel filtration of the active enzyme in 0.1% Triton X-100 gave an Mr approximately 270,000-300,000, suggesting extensive self-aggregation. With both tributyrin and triolein, the pH optimum of the purified enzyme was 4.0 and activity extended from pH 2.0 to 8.0. In contrast to purified human pancreatic lipase, lingual lipase hydrolyzed triglyceride emulsions and mixed micelles stabilized with both short-chain (dihexanoyl) and long-chain (egg) lecithin and were inhibited only slightly (18-25%) by micellar concentrations of two common bile salts, taurodeoxycholate and taurocholate. Our results suggest that the hydrolysis of dietary fat by lingual lipase may extend from the pharynx through the esophagus and stomach and into the upper small intestine.


1981 ◽  
Vol 59 (11-12) ◽  
pp. 916-920 ◽  
Author(s):  
Hugh S. Keeping ◽  
Shioko Kimura ◽  
Jane Lovsted ◽  
Peter H. Jellinck

Peroxidase was purified 3700-fold from homogenates of estradiol-treated rat uteri by affinity chromatography on concanavalin A (ConA) – Sepharose followed by gel filtration on Bio-Gel P-150 with high recovery of enzyme. A single protein (molecular weight (MW) 45 000) staining for heme was shown by sodium dodecyl sulfate – polyacrylamide gel electrophoresis to be present in the peak fractions of enzymic activity eluted from the ConA–Sepharose column. This protein had the same mobility as bovine lactoperoxidase (MW 78 000) in a cationic gel electrophoretic system under nondenaturing conditions. Peroxidase activity in a NaCl extract of the uterus was lower than that in a CaCl2 extract but was unaffected by prolonged storage at −20 °C. In contrast, the CaCl2-extracted enzyme lost much, of its activity under these conditions by a process which could be prevented by the addition of glycerol. The sulfhydryl reagent, N-ethylmaleimide, which caused a marked increase in the activity of uterine peroxidase, provided only partial protection against inactivation during storage of CaCl2 extracts of this enzyme at low temperature.


1988 ◽  
Vol 254 (3) ◽  
pp. C372-C382 ◽  
Author(s):  
M. Dunand ◽  
J. P. Kraehenbuhl ◽  
B. C. Rossier ◽  
M. L. Aubert

The binding characteristics of the prolactin (PRL) receptors present in toad (Bufo marinus) kidneys were investigated and compared to those of PRL receptors present in rabbit mammary glands. The molecular characteristics of the Triton X-100 solubilized renal and mammary PRL receptors were assessed by gel filtration and by migration analysis on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) after affinity labeling of the binding sites with 125I-human growth hormone. Similar results were obtained for both receptors. Partial purification of the toad PRL receptor could be achieved by affinity chromatography. The molecular weight of this purified receptor could be determined by analysis on SDS-PAGE. With the use of a polyclonal antiserum raised against a purified preparation of rabbit mammary PRL receptor, one or several antigenic epitope(s) could be identified on the core of the toad renal PRL receptor. In conclusion, although the structure and the biological role(s) of PRL have substantially changed during evolution, the receptor for this hormone has retained many of its structural features as could be assessed between an amphibian and a mammalian species on functionally different target tissues.


1984 ◽  
Vol 217 (1) ◽  
pp. 129-133 ◽  
Author(s):  
L J Takemoto ◽  
J Hansen ◽  
D B Farber ◽  
D Souza ◽  
D J Takemoto

A light-activated phosphodiesterase (PDE) from retinal rod outer segments (ROS) has been strongly implicated as a possible mediator in the propagation of the visual response. In view of the probable importance of this enzyme in the visual system, a comparison of the PDE proteins from ROS of different evolutionary species was made. Partial purification of the PDE, as measured by enzymic activity, followed by resolution of the protein components on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, indicated that the major Coomassie Blue-staining species in the ROS of all species studied is a doublet of 84000-88000 Da. After radioiodination, this doublet was converted in all but the frog proteins into a single band of 85000 Da. Two-dimensional tryptic peptide mapping of the radioiodinated peptides indicated that at least six major peptides of the putative PDE have been conserved in all of the species studies. If this protein is indeed associated with PDE activity, such conserved peptides may play an important role in the catalytic and/or regulatory functions of the enzyme.


1981 ◽  
Vol 45 (03) ◽  
pp. 219-224 ◽  
Author(s):  
W E Laug

SummaryEndothelial cells were obtained from the aortae of newborn calves and cloned. High plasminogen activator (PA) activity was detected in the supernatant medium and the cell lysates of confluent cultures. The PA activity in the growth medium increased steadily during 12 hrs of incubation, indicating active enzyme secretion by these cells. Sodium dodecyl sulphate (SDS) polyacrylamide gel electrophoresis of the concentrated medium demonstrated the presence of four plasminogen activators with apparent molecular weights of 77,000 (±3000), 43,000 (±2000), 26,000 (±1500) and 14,500 (±1500) respectively. The 43,000, 26,000 and 14,500 molecular weight forms could be converted to radioactive derivates by active site labeling with 3H diisopropyl fluorophosphate (3H DFP) while the 77,000 Dalton form took up only traces of this radioactively labeled compound. The 43,000 molecular weight form was partially purified by means of salt precipitation and gel filtration. This enzyme preparation activated plasminogen by proteolytic cleavage with maximum activity at pH 7.5-8.5 and demonstrated a specific activity of 80,000 CTA (Committee on Thrombolytic Agents) units/mg protein when tested on 125I-fibrin in the presence of plasminogen. This PA was rapidly and irreversibly inhibited by diisopropyl fluorophosphate (DFP), suggesting that it was a serine protease. The partially purified enzyme was extremely labile at temperatures from 0-60° C, but could be stabilized by lowering the pH to 3 or by the addition of albumin.


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