Abstract：
:Two GH43 β-xylosidases, RS223-BX from a rice straw metagenomic library, and BoXA from Bacteroides ovatus, that share similar amino acid sequences (81% identical) and 19 of 20 active-site residues, were compared by using site-directed mutagenesis of Asp and His residues implicated in metal binding. Thus, RS223-BX is strongly activated by divalent-metal cations and the previously published X-ray structure of this enzyme shows that a Ca2+ cation is chelated by an active-site Asp carboxyl group and an active-site His. Mutation to Ala causes 90% loss of activity for the Asp mutant and 98% loss of activity for the His mutant, indicating their importance to catalysis. For the other enzyme (BoXA), mutation to Ala causes 20% loss of activity for the His mutant and 40% gain of activity for the Asp mutant, indicating the lack of importance for activity of the native residues and the lack of metal-dependency, given that the Asp residue occupies the active site to secure the metal cation in known metal ion dependent GH43 xylosidases. The high activity of the BoXA mutants compared to that of the analogous RS223-BX mutants further undermines the possibility that BoXA maintains a tightly bound metal cofactor resistant to EDTA extraction. The results strengthen our conclusion that the very similar proteins differ in one being metal ion dependent and one not.
journal_name
Enzyme Microb Technoljournal_title
Enzyme and microbial technologyauthors
Jordan DB,Stoller JR,Kibblewhite RE,Chan VJ,Lee CC,Wagschal Kdoi
10.1016/j.enzmictec.2018.03.007subject
Has Abstractpub_date
2018-07-01 00:00:00pages
29-32eissn
0141-0229issn
1879-0909pii
S0141-0229(18)30133-9journal_volume
114pub_type
杂志文章abstract：:The full utilization of hemicellulose sugars (pentose and exose) present in lignocellulosic material, is required for an efficient bio-based fuels and chemicals production. Two recombinant thermophilic enzymes, an endo-1,4-β-mannanase from Dictyoglomus turgidum (DturCelB) and an α-galactosidase from Thermus thermophil...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2017.12.008
更新日期：2018-04-01 00:00:00
abstract：:In this work, porous biochar derived from sugarcane bagasse was prepared and then coated with different amounts of chitosan (C@CS) for cellulase immobilization. Cellulase was covalently immobilized on the support by using glutaraldehyde as a linker. The chemical characteristics and morphology of the samples were deter...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2020.109561
更新日期：2020-08-01 00:00:00
abstract：:The family B DNA polymerase gene from the euryarchaeon Thermococcus barophilus Ch5 (Tba5) contains an open reading frame of 6198 base pairs that encodes 2065 amino acid residues. The gene is split by three inteins that must be spliced out to form the mature DNA polymerase. A Tba5 DNA polymerase gene without inteins (g...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.02.004
更新日期：2016-05-01 00:00:00
abstract：:Filamentous fungal secretomes comprise highly dynamic sets of proteins, including multiple carbohydrate active enzymes (CAZymes) which are able to hydrolyze plant biomass polysaccharides into products of biotechnological interest such as fermentable sugars. In recent years, proteomics has been used to identify and qua...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章,评审
doi：10.1016/j.enzmictec.2017.08.007
更新日期：2018-02-01 00:00:00
abstract：:beta-amylases are used in production of maltose syrup. It is shown that sweet potato beta-amylase can be purified by affinity precipitation with alginate with 80% activity yield and 44 fold purification. SDS-PAGE of the purified protein showed a single band and a subunit weight of 50 kDa. Preliminary data with soybean...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(01)00338-6
更新日期：2001-06-07 00:00:00
abstract：:Ergosterol, like cholesterol, has many beneficial physiological activities, and because it has no adverse clinical problem with cholesterol, it is a substance that can be used as a biomaterial in the food and cosmetics industry. However, ergosterol has low oil solubility and is easily crystallized, which is problemati...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2020.109581
更新日期：2020-09-01 00:00:00
abstract：:Turanose is a natural isomer of sucrose. It is an emerging functional sweetener of the next generation. Turanose is catalytically synthesized from the sucrose biomass by employing amylosucrase enzyme. In this study, a novel gene encoding amylosucrase (Asmet) has been identified from the metagenome of a thermal aquatic...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2019.109372
更新日期：2019-12-01 00:00:00
abstract：:Direct esterifications using a nylon-immobilized lipase from Candida cylindracea were carried out in batch and continuous-flow reactors. The immobilized enzyme was effective in catalyzing the synthesis of ethylpropionate, isoamylpropionate, and isoamylbutyrate. With ethanol dissolved in hexane as a substrate, the maxi...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(92)90054-r
更新日期：1992-11-01 00:00:00
abstract：:Fremyella diplosiphon is a freshwater cyanobacterium that has great potential as a biofuel agent due to its ability to grow in low light intensity and acclimation to different wavelengths. To enhance its halotolerance for growth in 35gL-1 sodium chloride (NaCl), plasmids harboring hemolysin B (hlyB) and malate dehydro...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2017.04.009
更新日期：2017-08-01 00:00:00
abstract：:The stabilization of fungal cellulases by spray drying, the thermal stability of Penicillium occitanis cellulases and the effect of some additives were studied. We observed that CMCase activity presents a good stability at 50 degrees C, even after 60 h of incubation. On the other hand, beta-glucosidase activity was mo...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(00)00322-7
更新日期：2001-02-01 00:00:00
abstract：:Marine microbes have gained significant attention as potential biofactories for broad spectrum bioactive compounds. In the recent years, bioactive biosurfactants have warranted renewed interest from both environmental and clinical sectors as anti-biofilm agents due to their excellent properties of dispersing microbial...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2018.09.008
更新日期：2019-01-01 00:00:00
abstract：:A new bi-modular, wide pH spectrum and highly active xylanase KRICT PX3 (JF320814) isolated from Paenibacillus terrae HPL-003 (KCTC11987BP) has been cloned and expressed in Escherichia coli. Purified recombinant xylanase KRICT PX-3 (1,620 bp, 540aa, NCBI accession number JF320814) showed highly active at 55°C in pH 4....
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2013.09.002
更新日期：2014-01-10 00:00:00
abstract：:Kinetic resolution of sec-alcohols is a green process with biocatalyst. Candida antarctica lipase B (CALB) displayed on Pichia pastoris cell-surface (Pp-CALB) was characterized in kinetic resolution of sec-alcohols with different structures. The reaction parameters including acyl donors, molar ratio of substrates, sol...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2017.11.005
更新日期：2018-03-01 00:00:00
abstract：:The cellulase and xylanase genes of filamentous Trichoderma fungi exist under carbon catabolite repression mediated by the regulator carbon catabolite repressor (CREI). Our objective was to find the role of CREI in a cellulase-hyperproducing mutant of Trichoderma koningii, and address whether enzyme production can be ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2013.04.007
更新日期：2013-07-10 00:00:00
abstract：:The effect of treatment with various intercalating dyes on the ability to produce antibiotics in Micromonospora rosaria and Micromonospora purpurea was studied. Treatment with acriflavine resulted in a high frequency loss of antibiotic productivity in both species. In M. rosaria, the loss of antibiotic-producing abili...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(90)90128-d
更新日期：1990-08-01 00:00:00
abstract：:Before applying nanotechnologies in biomedical and environmental areas it is advised to study interactions of nanoparticles and other nanomaterials with biomacromolecule present in living system. Moreover there is scarcity of reports on interactions between nanoparticles and biomaterials. In present report a rapid, ec...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.06.005
更新日期：2016-10-01 00:00:00
abstract：:Monod kinetic parameters provide information required for kinetic analysis of anaerobic oxidation of methane coupled to denitrification (AOM-D). This information is critical for engineering AOM-D processes in wastewater treatment facilities. We first experimentally determined Monod kinetic parameters for an AOM-D enri...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2017.05.005
更新日期：2017-09-01 00:00:00
abstract：:The hydrolytic activity of a thermophilic cyclomaltodextrinase (CMD) from Anoxybacillus flavithermus ZNU-NGA and a representative single mutant were investigated against soluble substrates including α-, β- and γ-cyclomaltodestrines (CDs). Based on the occurrence of arginine (Arg) at position 403 in some homologue prot...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2019.109421
更新日期：2019-12-01 00:00:00
abstract：:Addition of non-ionic surfactants (NIS) is known to accelerate enzymatic lignocellulose hydrolysis. The mechanism behind this accelerating effect is still not elucidated but has been hypothesized to originate from favorable NIS-lignin interactions which alleviate non-productive adsorption of cellulases to lignin. In t...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2011.06.015
更新日期：2011-09-10 00:00:00
abstract：:Corynebacterium glutamicum is an important industrial organism for the production of a variety of biological commodities. We discovered a promoter encoded by the gene NCgl2319 in C. glutamicum, which could be induced by benzyl alcohol, could be used as an efficient tunable expression system. In initial attempts, this ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2020.109651
更新日期：2020-11-01 00:00:00
abstract：:In the present investigation, the bacterium Escherichia coli (VM1) was isolated from a marine sediments of Ennore coastal water along southeast coast of India was exploited for its capability of Ag NPs synthesis. The derived nanoparticles were characterized employing ultraviolet-visible (UV-vis) spectroscopy, Fourier ...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.09.008
更新日期：2016-12-01 00:00:00
abstract：:Foaming, a proficient method for the recovery of surface active solutes from dilute solutions, was successfully applied for the concentration of the lipopeptide biosurfactant Surfactin from B. subtilis ATCC 21332 cell culture broths. Foaming was only partially successful in concentrating Surfactin when applied as a se...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(00)00327-6
更新日期：2001-03-08 00:00:00
abstract：:Photothermal therapy (PTT) is a minimally invasive and effective cancer treatment method and has a great potential for innovating the conventional chemotherapy approaches. Copper sulfide (CuS) exhibits photostability, low cost, and high absorption in near infrared region, and is recognized as an ideal candidate for PT...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.04.002
更新日期：2016-12-01 00:00:00
abstract：:The methyl ester of 2-benzoxazolon-3-yl-acetic acid was used as an acyl donor in the penicillin amidase-catalysed transfer reaction to 7-aminodesacetoxycephalosporanic acid. The synthesis of 7-(2-benzoxazolon-3-yl-acetamido)-desacetoxycephalosporanic acid was carried out as a kinetically controlled reaction. A charact...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/0141-0229(92)90144-d
更新日期：1992-06-01 00:00:00
abstract：:The yeast Pichia pastoris is a widely used host for recombinant protein expression, and has recently been engineered for whole-cell biocatalysis. The inducible P(AOX) and constitutive P(GAP) promoters are commonly employed. In this study, the S-adenosyl-L-methionine (SAM) biosynthesis and degradation efficiency of two...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2013.09.003
更新日期：2014-02-05 00:00:00
abstract：:The effect of hexoses (glucose and galactose) addition to the feed xylose mineral medium of Debaryomyces hansenii chemostat cultures grown at a constant dilution rate of 0.055 h(-1) was studied. Xylitol was the major product detected amongst all tested conditions. The maximal values for xylitol yield and volumetric pr...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/s0141-0229(00)00166-6
更新日期：2000-06-01 00:00:00
abstract：:Global substitution of canonical amino acids (cAAs) with noncanonical (ncAAs) counterparts in proteins whose function is dependent on post-translational events such as cofactor binding is still a methodically challenging and difficult task as ncAA insertion generally interferes with the cofactor biosynthesis machinery...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2017.06.014
更新日期：2017-11-01 00:00:00
abstract：:Progesterone 5β-reductases (P5βRs) are involved in 5β-cardenolide formation by stereo-specific reduction of the △4,5 double bond of steroid precursors. In this study a steroid 5β-reductase was identified in Capsella rubella (CrSt5βR1) and its function in steroid 5β-reduction was validated experimentally. CrSt5βR1 is c...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2019.109483
更新日期：2020-03-01 00:00:00
abstract：:The gene encoding a cold-adapted phospholipase A(1) (PLA(1)) from a psychrotrophic, glacier soil bacterium Serratia sp. xjF1 was cloned by two-step PCR (general PCR and TAIL-PCR). The full-length fragment comprised two open reading frames plA and plS. The gene product of plA encoding 320 amino acids with a molecular w...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2007.09.004
更新日期：2008-01-01 00:00:00
abstract：:Two novel glycosyl hydrolase family 5 (GH5) β-mannanases (AoMan5A and AoMan5B) were identified from Aspergillus oryzae RIB40 by genome mining. The AoMan5A contains a predicted family 1 carbohydrate binding module (CBM-1), located at its N-terminal. The AoMan5A, AoMan5B and truncated mutant AoMan5AΔCL (truncating the N...
journal_title：Enzyme and microbial technology
pub_type： 杂志文章
doi：10.1016/j.enzmictec.2016.08.003
更新日期：2016-11-01 00:00:00
