Purification, Biochemical Characterization and Decolorization Efficiency of Laccases from Peach and Cherry Cultures of Pleutorus eryngii: A Comparative Study

2020 ◽  
Vol 27 (7) ◽  
pp. 623-634 ◽  
Author(s):  
Merve Akpinar ◽  
Raziye Ozturk Urek

Background:: Laccases (Lacs) are used potentially in industrial and biotechnological applications such as decolorization of dyes, degradation of industrial effluents, delignification, etc. thanks to their large varieties of substrate specificities and excellent catalytic efficiencies. The efficient utilizations of Lacs in these applications mostly depend on the identifying their biochemical properties. Objective: The goal of this research is to investigate the purification, biochemical characterization and decolorization efficiencies of Lacs. Methods: Pleurotus eryngii was incubated on peach (PC) and cherry (CC) wastes under optimized solid state fermentation conditions. Then, the enzymes extracts were purified by ammonium sulfate precipitation, anion exchange chromatography, gel filtration, respectively. Lacs fractions were subjected to electrophoretic analyses as well as their structural and kinetic characteristics. Also, the effects of selected chemical agents on purified Lacs activities and determination of decolorization efficiencies were studied. Results: As the results of purification processes of Lacs from both cultures, 3.94-fold purification was obtained for PC, while it was 5.34 for CC. The electrophoretic results of purified Lacs illustrated the single bands of protein (30±1 kDa) in accordance with the results after gel filtration. The Km values of Lacs from PC and CC were respectively detected as 1.1381 and 0.329 mM for ABTS. The selected agents partially/completely inhibited Lac activities. The highest decolorization efficiencies of purified Lacs from PC and CC were separately obtained as 53 and 11.8%. Conclusion: The results clearly indicated that the performances of Lacs from both cultures in decolorization application are different from each other depending their activities, biochemical and kinetic characteristics.

2002 ◽  
Vol 282 (3) ◽  
pp. C567-C577 ◽  
Author(s):  
Dany Salvail ◽  
Martin Cloutier ◽  
Eric Rousseau

We describe the biochemical properties of an eicosanoid-modulated Cl−channel and assess the mechanisms by which the epoxyeicosatrienoic acids (EETs) alter both its unitary conductance and its open probability ( P o). After a purification protocol involving wheat-germ agglutinin affinity and anion-exchange chromatography, the proteins were sequentially inserted into liposomes, which were then fused into PLBs. Functional and biochemical characterization tests confirm that the Cl− channel is a 55-kDa glycosylated monomer with voltage- and Ca2+concentration-independent activity. 5,6- and 8,9-EET decreased the conductance of the native channel (control conductance: 70 ± 5 pS in asymmetrical 50 mM trans/250 mM cis CsCl) in a concentration-dependent manner, with respective 50% inhibitory concentration values of 0.31 and 0.42 μM. These regioisomers similarly decreased the conductance of the purified channel (control conductance value: 75 ± 5 pS in asymmetrical 50 mM trans/250 mM cis CsCl), which had been stripped of its native proteic and lipidic environment. On the other hand, 5,6- and 8,9-EETs decreased the P o of the native channel with respective 50% inhibitory concentration values of 0.27 and 0.30 μM but failed to alter the P o of the purified protein. Thus we suggest that the effects of these EETs on channel conductance likely result from direct interactions of EET− anions with the channel pore, whereas the alteration of P o requires a lipid environment of specific composition that is lost on solubilization and purification of the protein.


1980 ◽  
Vol 187 (3) ◽  
pp. 647-653 ◽  
Author(s):  
K Arakawa ◽  
M Yuki ◽  
M Ikeda

Tryptensin, a vasopressor substance generated from human plasma protein fraction IV-4 by trypsin, has been isolated and the amino acid composition analysed. The procedures used for the isolation were: (a) adsorption of the formed tryptensin on Dowex 50W (X2; NH4+ form); (b) gel filtration through Sephadex G-25; (c) cation-exchange chromatography on CM-cellulose; (d) anion-exchange chromatography on DEAE-cellulose; (e) re-chromatography on CM-cellulose; (f) gel filtration on Bio-Gel P-2; (g) partition chromatography on high-pressure liquid chromatography. The homogeneity of the isolated tryptensin was confirmed by thin-layer chromatography and thin-layer electrophoresis. The amino acid analysis of the hydrolysate suggested the following proportional composition: Asp, 1; Val, 1; Ile, 1; Tyr, 1; Phe, 1; His, 1; Arg, 1; Pro, 1. This composition is identical with that of human angiotensin.


1981 ◽  
Vol 60 (3) ◽  
pp. 331-334 ◽  
Author(s):  
F. Gejyo ◽  
G. Ito ◽  
Y. Kinoshita

1. An unidentified ninhydrin-positive substance of an acidic nature was detected in the plasma of uraemic patients. This substance was isolated from haemodialysate by ion-exchange chromatography and gel filtration, and identified as a sulphur-containing amino acid: N-monoacetylcystine. 2. The quantitative determination of sulphur amino acids in plasma revealed that the plasma levels of cysteic acid, homocysteic acid, taurine, cystine and cystathionine as well as N-monoacetylcystine in uraemic patients were markedly higher than in normal subjects (P < 0.001 for each). However, the plasma levels of methionine in uraemic patients were within normal limits.


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