scholarly journals LACCASE ISOLATION FROM SPENT MUSHROOM WASTE (AGARICUS BISPORUS): PARTIAL PURIFICATION, CHARACTERIZATION, IMMOBILIZATION AND BIOTECHNOLOGICAL APPLICATION

Author(s):  
Güliz AK ◽  
Habibe YILMAZ ◽  
Şenay ŞANLIER
Author(s):  
Hicham Gouzi ◽  
Abdelhafid Benmansour

Polyphenol oxidase (PPO) from mushrooms (Agaricus bisporus (J.E.Lange) Imbach) was partially purified and characterized. The enzyme exhibited both monophenolase and diphenolase activities that were measured spectrophotometrically using L-tyrosine and pyrogallol as substrates. A two-fold purification in both activities was achieved by ammonium sulfate fractionation. The monophenolase activity was 3.35 EU/ml, and the diphenolase activity was 189.3 EU/ml. PPO was relatively stable at -15°C for 44 days. The enzyme was not very heat stable, and its activity decreased when incubated at the temperatures higher than 35°C. PPO activity showed two pH optima, at 5.3 and 7.0 at 25°C when pyrogallol was used as the substrate.Mono-, di- and triphenols were substrates for PPO. Using Vmax/Km as a specificity constant, pyrocatechol was the better substrate followed by pyrogallol. The kinetic parameters of the enzyme were: Vmax = 78 EU/min/ml, Km = 1.4 mM and KS = 250 mM for pyrogallol and Vmax = 168 EU/min/ml, Km = 0.40 mM and KS = 270 mM for the pyrocatechol. Of the inhibitors tested, competitive-type inhibition was observed with benzoic acid and sodium azide. A mixed-type inhibition was observed with L-cysteine and sodium fluoride.


Author(s):  
K. S. McCarty ◽  
R. F. Weave ◽  
L. Kemper ◽  
F. S. Vogel

During the prodromal stages of sporulation in the Basidiomycete, Agaricus bisporus, mitochondria accumulate in the basidial cells, zygotes, in the gill tissues prior to entry of these mitochondria, together with two haploid nuclei and cytoplasmic ribosomes, into the exospores. The mitochondria contain prominent loci of DNA [Fig. 1]. A modified Kleinschmidt spread technique1 has been used to evaluate the DNA strands from purified whole mitochondria released by osmotic shock, mitochondrial DNA purified on CsCl gradients [density = 1.698 gms/cc], and DNA purified on ethidium bromide CsCl gradients. The DNA appeared as linear strands up to 25 u in length and circular forms 2.2-5.2 u in circumference. In specimens prepared by osmotic shock, many strands of DNA are apparently attached to membrane fragments [Fig. 2]. When mitochondria were ruptured in hypotonic sucrose and then fixed in glutaraldehyde, the ribosomes were released for electron microscopic examination.


1991 ◽  
Vol 81 (3) ◽  
pp. 327-334 ◽  
Author(s):  
Cesar V. Mujer ◽  
Dale W. Kretchman ◽  
A. Raymond Miller

1995 ◽  
Vol 94 (4) ◽  
pp. 629-634 ◽  
Author(s):  
Mohamed Benichou ◽  
Gracia Martinez-Reina ◽  
Felix Romojaro ◽  
Jean-Claude Pech ◽  
Alain Latche

1973 ◽  
Vol 30 (02) ◽  
pp. 414-424 ◽  
Author(s):  
Ulla Hedner

SummaryA procedure is described for partial purification of an inhibitor of the activation of plasminogen by urokinase and streptokinase. The method involves specific adsorption of contammants, ion-exchange chromatography on DEAE-Sephadex, gel filtration on Sephadex G-200 and preparative electrophoresis. The inhibitor fraction contained no antiplasmin, no plasminogen, no α1-antitrypsin, no antithrombin-III and was shown not to be α2 M or inter-α-inhibitor. It contained traces of prothrombin and cerulo-plasmin. An antiserum against the inhibitor fraction capable of neutralising the inhibitor in serum was raised in rabbits.


1981 ◽  
Vol 45 (02) ◽  
pp. 121-126 ◽  
Author(s):  
Utako Okamoto ◽  
Noboru Horie ◽  
Yoko Nagamatsu ◽  
Jun-Ichiro Yamamoto

SummaryMilk plasminogen-activator was partially purified from human transitional milk collected at about 10 days after delivery, by a five-step procedure involving chloroform treatment, ammonium sulfate precipitation, and column chromatography on Sephadex G-150, CM Sephadex C-50 and DEAE Sephadex A-50. This gave milk-activator with a maximum purification factor of about 2,400-fold with respect to the skimmed milk. The CM Sephadex-step preparation showed, on polyacrylamide gel electrophoresis, a single plasminogen-activator activity band located between the bands of albumin and prealbumin of human serum. This preparation exhibited no kinin forming activity. The activator hydrolyzed acetyl-glycyl-L-lysine methyl ester with similar order kinetic constants to urokinase, and was inhibited strongly by diisopropyl-fluorophosphate. The molecular weight of the activator as estimated by gel filtration was approximately 86,000, the isoelectric points as estimated by gel isoelectric focusing were pH 7.2, 6.9 and 6.6, and the activator activity was not quenched by antiurokinase globulin, indicating that the milk-activator is a different entity from urokinase.


1974 ◽  
Vol 31 (03) ◽  
pp. 403-414 ◽  
Author(s):  
Terence Cartwright

SummaryA method is described for the extraction with buffers of near physiological pH of a plasminogen activator from porcine salivary glands. Substantial purification of the activator was achieved although this was to some extent complicated by concomitant extraction of nucleic acid from the glands. Preliminary characterization experiments using specific inhibitors suggested that the activator functioned by a similar mechanism to that proposed for urokinase, but with some important kinetic differences in two-stage assay systems. The lack of reactivity of the pig gland enzyme in these systems might be related to the tendency to protein-protein interactions observed with this material.


Sign in / Sign up

Export Citation Format

Share Document