scholarly journals Biochemical Characterization of Two Rhamnogalacturonan Lyases From Bacteroides ovatus ATCC 8483 With Preference for RG-I Substrates

2022 ◽  
Vol 12 ◽  
Author(s):  
Weiyang Wang ◽  
Yibing Wang ◽  
Haoting Yi ◽  
Yang Liu ◽  
Guojing Zhang ◽  
...  
Keyword(s):  
Biochemical Characterization ◽  
Maximal Activity ◽  
Divalent Metal ◽  
Type I ◽  
Divalent Metal Ions ◽  
Short Side ◽  
Glycosidic Bonds ◽  
Bacteroides Ovatus ◽  
Rhamnogalacturonan Lyase

Rhamnogalacturonan lyase (RGL) cleaves backbone α-1,4 glycosidic bonds between L-rhamnose and D-galacturonic acid residues in type I rhamnogalacturonan (RG-I) by β-elimination to generate RG oligosaccharides with various degrees of polymerization. Here, we cloned, expressed, purified and biochemically characterized two RGLs (Bo3128 and Bo4416) in the PL11 family from Bacteroides ovatus ATCC 8483. Bo3128 and Bo4416 displayed maximal activity at pH 9.5 and pH 6.5, respectively. Whereas the activity of Bo3128 could be increased 1.5 fold in the presence of 5 mM Ca2+, Bo4416 required divalent metal ions to show any enzymatic activity. Both of RGLs showed a substrate preference for RG-I compared to other pectin domains. Bo4416 and Bo3128 primarily yielded unsaturated RG oligosaccharides, with Bo3128 also producing them with short side chains, with yields of 32.4 and 62.4%, respectively. Characterization of both RGLs contribute to the preparation of rhamnogalacturonan oligosaccharides, as well as for the analysis of the fine structure of RG-I pectins.

Purification and Characterization of Three Extracellular Proteinases Produced by Pseudomonas fluorescens INIA 745, an Isolate from Ewe's Milk

1999 ◽  
Vol 62 (5) ◽  
pp. 543-546 ◽  
Author(s):  
J. FERNÁNDEZ ◽  
A. F. MOHEDANO ◽  
P. GAYA ◽  
M. MEDINA ◽  
M. NUÑEZ
Keyword(s):  
Pseudomonas Fluorescens ◽  
Culture Medium ◽  
Inhibitory Effect ◽  
Divalent Metal ◽  
Divalent Metal Ions ◽  
Purification And Characterization ◽  
Ph Optimum ◽  
Extracellular Proteinases ◽  
Ewe's Milk

Three proteinases were isolated from culture medium of Pseudomonas fluorescens INIA 745 and purified to homogeneity by a combination of Phenyl-Sepharose, DEAE-Sepharose, and Sephadex G-100 chromatography. Optimal temperature for enzymatic activity was 45°C for all three proteinases. The pH optimum of proteinases I and II was found to be 7.0, while that of proteinase III was 8.0. Divalent metal ions like Cu2+, Co2+, Zn2+, Fe2+, and Hg2+ were inhibitory to proteinase activity while Ca2+, Mg2+, and Mn2+ had little or no inhibitory effect. The three enzymes were strongly inhibited by EDTA and 1,10-phenantroline and partially by cysteine. The three enzymes are metalloproteinases since they were inhibited by chelators and reactivated by Co2+, Mn2+, Cu2+, and Zn2+. The Km values of proteinases I, II, and III for casein were calculated to be 3.2, 2.6, and 5.2 mg/ml, respectively. Proteinases II and III rapidly degraded β-casein, with preference to αs1-casein, whereas proteinase I hydrolyzed both casein fractions at a slow rate.

Expression and biochemical characterization of a novel type I pullulanase from Bacillus megaterium

2016 ◽  
Vol 39 (3) ◽  
pp. 397-405 ◽  
Author(s):  
Shaoqing Yang ◽  
Qiaojuan Yan ◽  
Qingdan Bao ◽  
Jingjing Liu ◽  
Zhengqiang Jiang
Keyword(s):  
Bacillus Megaterium ◽  
Biochemical Characterization ◽  
Type I

Biochemical Characterization of a GH43 β-Xylosidase from Bacteroides ovatus

2016 ◽  
Vol 182 (1) ◽  
pp. 250-260 ◽  
Author(s):  
Douglas B. Jordan ◽  
J. Rose Stoller ◽  
Charles C. Lee ◽  
Victor J. Chan ◽  
Kurt Wagschal
Keyword(s):  
Biochemical Characterization ◽  
Bacteroides Ovatus

scholarly journals Expression and characterization of thermotolerant lipase with broad pH profiles isolated from an AntarcticPseudomonassp strain AMS3

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2420 ◽  
Author(s):  
Wahhida Latip ◽  
Raja Noor Zaliha Raja Abd Rahman ◽  
Adam Thean Chor Leow ◽  
Fairolniza Mohd Shariff ◽  
Mohd Shukuri Mohamad Ali
Keyword(s):  
Molecular Weight ◽  
Enzyme Activity ◽  
Organic Solvent ◽  
Divalent Metal ◽  
Single Step ◽  
Divalent Metal Ions ◽  
Gene Encoding ◽  
Affinity Tags ◽  
Ph Range

A gene encoding a thermotolerant lipase with broad pH was isolated from an AntarcticPseudomonasstrain AMS3. The recombinant lipase AMS3 was purified by single-step purification using affinity chromatography, yielding a purification fold of approximately 1.52 and a recovery of 50%. The molecular weight was approximately ∼60 kDa including the strep and affinity tags. Interestingly, the purified Antarctic AMS3 lipase exhibited broad temperature profile from 10–70 °C and stable over a broad pH range from 5.0 to pH 10.0. Various mono and divalent metal ions increased the activity of the AMS3 lipase, but Ni2+decreased its activity. The purified lipase exhibited the highest activity in the presence of sunflower oil. In addition, the enzyme activity in 25% v/v solvents at 50 °C particularly to n-hexane, DMSO and methanol could be useful for catalysis reaction in organic solvent and at broad temperature.

Crystal structures of a dodecameric multicopper oxidase from Marinithermus hydrothermalis

2021 ◽  
Vol 77 (10) ◽  
pp. 1336-1345
Author(s):  
Joseph L. Paavola ◽  
Umberto Battistin ◽  
Craig M. Ogata ◽  
Millie M. Georgiadis
Keyword(s):  
Crystal Structures ◽  
Copper Ions ◽  
Closed Ball ◽  
Single Type ◽  
Type I ◽  
Divalent Metal Ions ◽  
Trinuclear Cluster ◽  
Concomitant Reduction ◽  
Red Dye

Multicopper oxidases (MCOs) represent a diverse family of enzymes that catalyze the oxidation of either an organic or a metal substrate with concomitant reduction of dioxygen to water. These enzymes contain variable numbers of cupredoxin domains, two, three or six per subunit, and rely on four copper ions, a single type I copper and three additional copper ions organized in a trinuclear cluster (TNC), with one type II and two type III copper ions, to catalyze the reaction. Here, two crystal structures and the enzymatic characterization of Marinithermus hydrothermalis MCO, a two-domain enzyme, are reported. This enzyme decolorizes Congo Red dye at 70°C in the presence of high halide concentrations and may therefore be useful in the detoxification of industrial waste that contains dyes. In two distinct crystal structures, MhMCO forms the trimers seen in other two-domain MCOs, but differs from these enzymes in that four trimers interact to create a dodecamer. This dodecamer of MhMCO forms a closed ball-like structure and has implications for the sequestration of bound divalent metal ions as well as substrate accessibility. In each subunit of the dodecameric structures, a Trp residue, Trp351, located between the type I and TNC sites exists in two distinct conformations, consistent with a potential role in facilitating electron transfer in the enzyme.

Synthesis and characterization of bis(imino)pyridine complexes of divalent Mg and Zn

2016 ◽  
Vol 45 (14) ◽  
pp. 5989-5998 ◽  
Author(s):  
Thomas W. Myers ◽  
Tobias J. Sherbow ◽  
James C. Fettinger ◽  
Louise A. Berben
Keyword(s):  
Electronic Structure ◽  
Metal Ions ◽  
Torsion Angle ◽  
Divalent Metal ◽  
Synthesis And Characterization ◽  
Divalent Metal Ions ◽  
Structural Comparison ◽  
Bond Lengths ◽  
Pyridine Complexes

The synthesis and electronic structure of bis(imino)pyridine (I2P) complexes of the divalent metal ions, Zn(ii) and Mg(ii) are reported, and a correlation between the ligand Cim–Cpy bond lengths with the ligand torsion angle is described. Structural comparison with a new complex of Al(iii) and previously reported Al(iii) complexes is included.

The purification and characterization of a β-glucosidase from Alcaligenes faecalis

1986 ◽  
Vol 64 (9) ◽  
pp. 914-922 ◽  
Author(s):  
Anthony G. Day ◽  
Stephen G. Withers
Keyword(s):  
Glucose Production ◽  
High Specificity ◽  
Alcaligenes Faecalis ◽  
Divalent Metal ◽  
Exchange Chromatography ◽  
Good Choice ◽  
Divalent Metal Ions ◽  
Purification And Characterization ◽  
Glucanase Activity

The β-glucosidase from Alcaligenes faecalis has been purified to homogeneity (880-fold purification, 11% yield) using a combination of classical techniques and medium pressure ion-exchange chromatography. It is a dimeric enzyme of monomer molecular weight 50 000 and has no specific requirement for divalent metal ions. It has a high specificity for β-glucosides and hydrolyses a wide variety of different chemical types with retention of configuration at the anomeric centre. It has no exo-β-1,4-glucanase activity. It is reversibly inhibited by a variety of sugars which have been shown previously to be very active against glucosidases, suggesting a normal mechanism of action. Measured Km values for cellobiose and p-nitrophenyl β-D-glucopyranoside are quite low (0.70 and 0.08 mM, respectively), making this a good choice for cocloning into a cellulase system optimized for glucose production.

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