scholarly journals Effect of hepatic injury on prolyl 3-hydroxylase and 4-hydroxylase activities in rat liver and on immunoreactive prolyl 4-hydroxylase concentrations in the liver and serum

1978 ◽  
Vol 170 (1) ◽  
pp. 129-135 ◽  
Author(s):  
J Risteli ◽  
L Tuderman ◽  
K Tryggvason ◽  
K I Kivirikko

After severe hepatic injury induced by dimethylnitrosamine, approximately a 4-fold increase in hepatic prolyl 4-hydroxylase activity occurred within 4 days, whereas the increases in total immunoreactive prolyl 4-hydroxylase protein and in prolyl 3-hydroxylase activity were only about 1.4-fold. The different magnitudes of the increases in the prolyl 4-hydroxylase and 3-hydroxylase activities were verified after partial purification of the enzymes by gel filtration. The data support previous reports indicating differential increases in the activities of individual enzymes of collagen biosynthesis in hepatic injury. Separation of prolyl 4-hydroxylase tetramers from the monomer-size protein by gel filtration indicated that the increase in enzyme activity was similar to that in enzyme tetramers, and an increase had also occurred in the ratio of enzyme tetramers to total enzyme protein. Thus the specific activity of the tetramers had remained unchanged in liver injury. The administration of dimethylnitrosamine was also accompanied by a marked increase in the immunoreactive prolyl 4-hydroxylase protein concentration in the serum, and a similar effect was also noted after carbon tetrachloride administration, results suggesting that the increases originated in the liver.

2018 ◽  
Vol 22 (2) ◽  
pp. 47
Author(s):  
Akhmad Solikhin ◽  
Apon Zaenal Mustopa ◽  
Suharsono Suharsono ◽  
Wendry Setiyadi Putranto

   Lactobacillus casei WSP-derived an aspartic protease was sequentially purified by using chromatography gel filtration sephadex G-50. It resulted in a 22.81-fold increase of specific activity (51.5 U/mg) with a final yield of 1.9%. The estimated molecular weight of the purified enzyme was 37 kDa and showed gelatinolytic activity in zymogram assay. The enzyme exhibited optimum activity at 40ºC and pH 6 with casein as the substrate. Enzyme activity was significantly inhibited by pepstatin A (0.5 mM and 1 mM), confirming that this enzyme is a group of aspartic proteases, while other inhibitors such as EDTA, PMSF and iodoacetic acid showed no inhibition effect on the activity of enzyme. The addition of metal ion to the enzyme decreased enzyme activity, indicating the proteolytic enzyme was metal ion- dependent. Denaturant such as DDT tended to increase caseinolytic activity. Furthermore, this enzyme was capable of generating the new peptides from skimmed milk with the size 8 kDa, 10 kDa and 15 kDa. These peptides have potential as antibacterial and antioxidant agents.


1980 ◽  
Vol 188 (2) ◽  
pp. 529-534 ◽  
Author(s):  
D S Sachan ◽  
C L Hoppel

Rat kidney homogenates metabolize N6-trimethyl-lysine to N-trimethylammoniobutyrate, but not to carnitine. The first step in this conversion is the hydroxylation of trimethyl-lysine to form 3-hydroxy-N6-trimethyl-lysine. An assay system was developed in which hydroxylation of trimethyl-lysine is linear with respect to both time and homogenate protein concentration. The rate is 5 nmol of 3-hydroxy-N6-trimethyl-lysine formed/min per mg of homogenate protein. The cofactors required are ascorbate, alpha-oxoglutarate, FeSO4, and O2. Catalase and dithiothreitol give a 20% stimulation. Ca2+ produces a 2-fold increase in specific activity and cannot be replaced by Mg2+, Mn2+ or Zn2+. These last three bivalent cations lead to a decreased activity. Subcellular distribution studies demonstrate that trimethyl-lysine hydroxylase activity parallels the distribution profile of succinate dehydrogenase and citrate synthase. Thus trimethyl-lysine hydroxylase has a mitochondrial localization. Distribution of trimethyl-lysine hydroxylase activity between cortex and medulla of kidney if 67 and 33% respectively, similar to mitochondrial distribution.


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.


1985 ◽  
Vol 114 (1) ◽  
pp. 397-414
Author(s):  
Nicholas Platt ◽  
Stuart E. Reynolds

1. A semi-isolated caterpillar heart bioassay was used to detect the presence of endogenous cardioactive material in the CNS of Manduca sexta larvae. 2. Cardioactivity was detected in all nervous tissue examined. Most activity (about 70% of the total in the CNS) was in the ganglia of the abdominal nerve cord (ANC). Cardioactivity was also detected in the abdominal transverse nerves, the proctodeal nerves and the corpora cardiaca/corpora allata. The source with the highest specific activity was the frontal ganglion. 3. Two factors, separable by Sephadex gel filtration, were distinguished in extracts of ANC: CAF 1, which has an estimated relative molecular mass (Mr) of about 4000, and CAF2 for which Mr is probably less than 1000. Both factors are apparently peptides. Neither is similar to any known insect cardioaccelerator. 4. Both CAF 1 and CAF 2 are able to cause cardioacceleration when injected into tetrodotoxin-paralysed caterpillars. 5. CAF 2 is present in both larvae and in adults. CAF 1 is present only in the caterpillar. The larval heart responds to both factors; the adult heart responds only to CAF 2. 6. Partial purification of CAF 1 and CAF 2 by reverse-phase HPLC gives a single peak of bioactivity in each case. 7. The biological activity of CAF 1 is destroyed by α-chymotrypsin, but not by trypsin. CAF 2 is not attacked by trypsin or by α-chymotrypsin. Treatment with performic acid or cyanogen bromide destroys the activity of both CAF 1 and CAF 2.


1977 ◽  
Author(s):  
F.S. Markland ◽  
J. Chou ◽  
Y. Shih ◽  
H. Pirkle

A new procedure has been developed for large scale, rapid purification of crotalase, the thrombin-1ike enzyme from the venom of the eastern diamondback rattlesnake (Crotalus adamanteus). The three step procedure involves: (1) molecular sieve chromatography on Sephadex G-100 in 0.04 M Tris buffer containing 0.10 M sodium chloride, pH 7.1; (2) gradient elution from DEAE-cellulose with sodium acetate buffer, pH 7.0; and (3) affinity chromatography on p-aminobenzamidine Sepharose using a spacer of 6-aminohexanoic acid. Crotalase was eluted from the affinity resin by 0.05 M Tris buffer containing 0.10 M sodium chloride and 0.15 M benzamidine-hydrochloride, pH 9.0, after first washing with the Tris buffer containing 0.40 M sodium chloride. From the crude venom, pure enzyme was obtained with an overall recovery of 40-60% of clotting activity and a 90-100 fold increase in specific activity. Crotalase was shown to be pure by Polyacrylamide disk gel electrophoresis which gave one band. The molecular weight was estimated to be approximately 31,000 by gel filtration on a calibrated Sephadex G-100 column. Amino acid analysis was performed and the composition was shown to be very similar to that reported earlier (F.S. Markland and P.S. Damus, J. Biol. Chem. 246: 6460, 1971). Clotting activity of the enzyme was not inhibited by heparin, either with or without plasma, whereas, thrombin was rapidly inactivated by heparin in the presence of plasma. In conclusion, we have developed a rapid and reproducible procedure for isolation in high yield of large quantities of the thrombin-like enzyme from the venom of the eastern diamondback rattlesnake. Studies are continuing on the primary structure and possible clinical applications of this enzyme.


1983 ◽  
Vol 214 (1) ◽  
pp. 69-75 ◽  
Author(s):  
P B Moore ◽  
N Kraus-Friedmann

The hepatic microsomal fraction contains tightly bound calmodulin as demonstrated by affinity chromatography. When this calmodulin was partially removed by EGTA treatment (0.5 mM-EGTA), the uptake of 45Ca2+ by the microsomal vesicles was stimulated by added calmodulin and inhibited by trifluoperazine (TFP). The Ca2+-dependent ATPase was partially purified on a calmodulin column. This partial purification resulted in a 500-fold increase in the specific activity of the enzyme when measured in the presence of added calmodulin. Antibodies prepared against calmodulin prevented this stimulatory effect. The fraction eluted from the calmodulin column contained several protein bands indicating that the specific activity of the Ca2+-dependent ATPase is probably still underestimated. There are likely to be other calmodulin-sensitive processes present in the hepatic microsomal fraction.


1976 ◽  
Vol 158 (2) ◽  
pp. 369-376 ◽  
Author(s):  
J Risteli ◽  
L Tuderman ◽  
K I Kivirikko

Prolyl hydroxylase was purified from newborn rats by affinity chromatography using poly(L-proline), and antiserum to the enzyme was prepared in rabbits. The rat prolyl hydroxylase was similar to the chick and human enzymes with respect to specific activity, molecular weight and molecular weights of the polypeptide chains. The activity of prolyl hydroxylase and the content of immunoreactive enzyme were measured in rat liver as a function of age in experimental hepatic injury. Active prolyl hydroxylase comprised about 13.2% of the total immunoreactive protein in the liver of newborn rats and the value decreased to about 3.6% at the age of 420 days. This decrease was due to a decrease in the enzyme activity, whereas only minor changes were found in the content of the immunoreactive protein. In hepatic injury, a significant increase was found in the ratio of active enzyme to total immunoreactive protein, owing to an increase in the enzyme activity. The data indicate that prolyl hydroxylase activity in rat liver is controlled in part by a mechanism which does not involve changes in the content of the total immunoreactive protein.


2019 ◽  
Vol 23 (10) ◽  
pp. 46
Author(s):  
Saif M. Hasan ◽  
Firas T. Maher ◽  
Nagham Q. Kadhim

This study was done to partially purification of  topoisomerase IB from serum of diabetic patients using Gel filtration technique, by using Sephadex G 100 gel. A single peak in fraction four has been obtained, and the degree of purification (17.1) fold, enzyme yield (108.2%) and specific activity (0.189ng/mg). Kinetics studies for the partial purified enzyme were carried out which showed optimal concentration of  substrate which was (0.1ng/ml), Michael's - Menten constant (Km=0.033ng) and maximum velocity (Vmax=0.90 ng/ml), while optimum Temperature was (37C°) and optimum pH was (7.5). The molecular weight of the partial purified enzyme has been determined by gel electrophoresis method, in presence of polyacrylamide  gel and sodium dodecyl sulphate (SDS-PAGE) which showed that the approximated molecular weight was (66KD).   http://dx.doi.org/10.25130/tjps.23.2018.168 


1986 ◽  
Vol 55 (01) ◽  
pp. 024-030 ◽  
Author(s):  
T Kosugi ◽  
Y Ariga ◽  
M Nakamura ◽  
K Kinjo

SummaryThere has been no previous report indicating whether thrombin-like enzyme is contained in the venomof Trimeresurus flavoviridis whichhas the strongest toxic effect in the case of Habu bite. The presentstudy was undertaken to clarify the existence of thrombin-like enzyme in Trimeresurus flavoviridis venom. As a starting material, lyophilized crude venom of Trimeresurus flavoviridis was used, and ammonium sulphate fractionation, gel filtration using Sephadex G-25, Sephadex G-150 and arginine-Sepharose affinity chromatography were carried out to separate and purify a thrombin-like enzyme from the crude venom. The enzyme was purified to a 137-fold increase in specific activity and the purified preparation revealed a single band on SDS-PAGE. The molecular weight of the enzyme was estimated to be 65,000-70,000 daltons by means of SDS-PAGE and gel filtration, and its isoelectric point was pH 4.5-5.5. Furthermore, the optimal pH of the enzyme was in the range of pH 8.0 to 8.5. Some of the differences in enzymatic properties between this enzyme and bovine thrombin were studied. The snake enzyme could coagulate only rabbit plasma and convert only purified rabbit fibrinogen to fibrin gel. In addition, this thrombin-like enzyme released only fibrinopeptide A from purified rabbit fibrinogen and did not release fibrinopeptide B.


1967 ◽  
Vol 22 (2) ◽  
pp. 204-215 ◽  
Author(s):  
Ingrid Capesius ◽  
Gerhard Richter

A method for the isolation and purification of polynucleotide phosphorylase from the blue-green alga Anacystis nidulans is described. It consists in an initial fractional centrifugation which yields up to 70% of the enzyme associated with the ribosomal fraction while the RNA-polymerase together with the bulk DNA is mainly confined to the supernatant. The ribosomal fraction is then subjected to column chromatography (DEAE-cellulose) and gel filtration (Sephadex G-200) to obtain a 120 — 150 fold increase in specific activity over the crude extract. The enzyme is essentially free from nucleic acids, phosphatases, kinases and RNA-polymerase. With ADP, UDP or CDP as substrate the corresponding homopolymers poly-A, poly-U and poly-C, respectively, are synthesized with good yields; no lag phase occurs. Equimolar mixtures of these nucleoside diphosphates give rise to heteropolymers. The optimal formation of poly-G and of AGUC polymer, both of which have rather low yields under standard conditions is achieved by incubating at higher temperatures (45° and 60°) and by replacing Mg2⊕ by Mg2⊕. In the presence of inorganic phosphate the highly purified enzyme also catalyzes the cleavage, to nucleoside diphosphates, of synthetic polynucleotides and of native high molecular RNA from various organisms. The possible association of polynucleotide phosphorylase with the ribosomes and its function is discussed.


Sign in / Sign up

Export Citation Format

Share Document