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Due to its various biological activities, the roots of Brassica rapa (turnip), has been applied as a therapeutic agent in traditional medicine. The current study aimed to purify a plant peroxidase (POD; designated as TRP) from Algerian white turnip (B. rapa, variety rapa) roots, to homogeneity and to characterise it biochemically. The molecular weight of the purified TRP was determined to be ∼58 kDa as estimated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and high-performance liquid chromatography (HPLC). The TRP Reinheitzahl values (RZ) and specific activity were 2.9 and 14,500 U/mg, respectively. Its N-terminal sequence exhibited high identity with those of class III-PODs. TRP showed optimal activity at 55 °C and pH 6 (guaiacol), was completely inhibited by sodium azide (NaN3) and potassium cyanide (KCN) and exhibited greater catalytic efficiency than that of the well-known horseradish peroxidase (HRP) from Armoracia rusticana. TRP demonstrated antioxidant activities with 45% and 61.49% of 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS•) and hydroxyl (•OH) radical scavenging, respectively, as well as ferrous ion chelating (52.96%) and reducing (48.32%) powers. This study provides information regarding the potential role of TRP in enzyme therapy (as applied in the pharmaceutical and medicinal industries), with biological eradication of free radicals. [ABSTRACT FROM AUTHOR]

A novel extracellular lipase from a filamentous fungus Ascomycota strain, P22, was isolated from olive mill wastewater, then purified and characterized. This strain was identified as Penicillium crustosum Thom based on sequencing analyses. Penicilliumcrustosum Thom strain P22 lipase (PCrL) was purified 63-fold to homogeneity using ammonium sulfate precipitation and chromatography on a Q-Sepharose Fast Flow column, with a total yield of 34%. The purified PCrL had a molecular mass of 28 kDa, estimated by SDS-PAGE. The 20 NH2-terminal amino-acid residues showed a high degree of homology with those of other Penicillium lipases. The specific activity of PCrL at pH 9 and 37 °C were found to be 5000 and 10,000 U/mg on olive oil and trioctanoin emulsions, respectively. PCrL exhibited clear regioselectivity toward the sn-1 position of the surface-coated triglycerides which were esterified with α-eleostearic acid at the sn-1/3 position. PCrL was completely inhibited by 53 µM of Orlistat, 5 mM of phenylmethylsulfonylfluoride, and 2 mM of diiodopropyl fluorophosphate, suggesting that it belonged to the serine lipase family. PCrL showed high activity and stability in the presence of water-immiscible organic solvents, surfactant, and oxidizing agents, and showed considerable compatibility with commercial laundry detergents. Washing performance analysis revealed that it could effectively remove oil stains. Hence, PCrL has several attractive properties that make it a promising potential candidate for detergent formulations. [ABSTRACT FROM AUTHOR]

A novel extracellular lignin peroxidase (LiP) has been produced (65 U/mL) in potato dextrose broth (PDB)-optimized media by a white-rot Agaricomycetes fungus strain KB-DZ15 newly isolated from dead deciduous trees at Zimoula Forest (Tizi-Ouzou, Algeria). This strain was identified as Phlebia radiata based on internal transcribed spacer (ITS) rDNA gene sequencing. The peroxidase enzyme (called LiP PR40) was purified and characterised. The matrix-assisted laser desorption-ionization – time of flight mass spectrometry (MALDI-TOF/MS) analysis revealed that LiP PR40 enzyme was a monomer with a molecular mass of 40,125.31 Da. The 25 N-terminal residue sequence of LiP PR40 showed high similarity with those of fungi LiPs. Interestingly, LiP PR40 presents premium activity at pH 3 and 80 °C with specific activity and Reinheitzahl (RZ) level of 510 U/mg and 2.81, respectively. Furthermore, it was completely inhibited by sodium azide (NaN3) and potassium cyanide (KCN), suggesting the presence of haem components in its tertiary structure. More interestingly, LiP PR40 illustrated more upper catalytic efficiency and dye-decolorisation aptitude than that of commercial well-known horseradish peroxidase (HRP) from roots of Armoracia rustanica and the purified reported LiP BA45 from Bjerkandera adusta strain CX-9. Consequently, these properties make LiP PR40 a potential candidate for destaining synthetic-dyes and lignin-biodegradation. [ABSTRACT FROM AUTHOR]

Two novel protease genes sapA and sapN from the thermophilic Anoxybacillus kamchatkensis M1V and Melghiribacillus thermohalophilus Nari2AT strains respectively, encoding a polypeptide of 381 and 379 residues, were identified, cloned and successfully heterologously expressed in Escherichia coli BL21(DE3)pLysS. The deduced putative amino-acid residues of SAPA and SAPN enzymes evinced identity with proteases from Bacillus strains. The highest sequence identity value (95%) of SAPA was obtained with peptidase S8 from Bacillus subtilis WT 168, but with 16 amino-acids of difference. While, the highest sequence identity (97.10%) of SAPN was observed with Bacillus licheniformis MP1 protease, but with 10 difference residues. rSAPA and rSAPN enzymes were purified until homogeneity, characterized, and compared to wild-type proteases. The purified recombinant enzymes rSAPA and rSAPN were two monomers of about 28 and 30 kDa, correspondingly. rSAPA displayed the highest activity at pH 11 and 70°C. While, rSAPN displayed the highest activity at pH 10 and 75°C. To initiate structure-function relationships, a 3Dmodel of the Pro-SAPA and Pro-SAPN proteins were thereafter built based on the available structures of common proteases. The comparative molecular modeling studies with the less thermostable protease, revealed extra charged residues at the surface of SAPA and SAPN potentially participating in the formation of intermolecular hydrogen bonds with solvent molecules or generating salt bridges, therefore contributing to the higher thermal stability. [ABSTRACT FROM AUTHOR]