scholarly journals Green Oxidation of Amines by a Novel Cold-Adapted Monoamine Oxidase MAO P3 from Psychrophilic Fungi Pseudogymnoascus sp. P3

Molecules ◽  
2021 ◽  
Vol 26 (20) ◽  
pp. 6237
Author(s):  
Iga Jodłowska ◽  
Aleksandra Twarda-Clapa ◽  
Kamil Szymczak ◽  
Aneta M. Białkowska

The use of monoamine oxidases (MAOs) in amine oxidation is a great example of how biocatalysis can be applied in the agricultural or pharmaceutical industry and manufacturing of fine chemicals to make a shift from traditional chemical synthesis towards more sustainable green chemistry. This article reports the screening of fourteen Antarctic fungi strains for MAO activity and the discovery of a novel psychrozyme MAOP3 isolated from the Pseudogymnoascus sp. P3. The activity of the native enzyme was 1350 ± 10.5 U/L towards a primary (n-butylamine) amine, and 1470 ± 10.6 U/L towards a secondary (6,6-dimethyl-3-azabicyclohexane) amine. MAO P3 has the potential for applications in biotransformations due to its wide substrate specificity (aliphatic and cyclic amines, pyrrolidine derivatives). The psychrozyme operates at an optimal temperature of 30 °C, retains 75% of activity at 20 °C, and is rather thermolabile, which is beneficial for a reduction in the overall costs of a bioprocess and offers a convenient way of heat inactivation. The reported biocatalyst is the first psychrophilic MAO; its unique biochemical properties, substrate specificity, and effectiveness predispose MAO P3 for use in environmentally friendly, low-emission biotransformations.

2001 ◽  
Vol 358 (3) ◽  
pp. 607-614 ◽  
Author(s):  
Marie-Helene BEYLOT ◽  
Vincent A. McKIE ◽  
Alphons G. J. VORAGEN ◽  
Chantal H. L. DOESWIJK-VORAGEN ◽  
Harry J. GILBERT

To investigate the mechanism by which Pseudomonas cellulosa releases arabinose from polysaccharides and oligosaccharides, a gene library of P. cellulosa genomic DNA was screened for 4-methylumbelliferyl-α-l-arabinofuranosidase (MUAase) activity. A single MUAase gene (abf51A) was isolated, which encoded a non-modular glycoside hydrolase family (GH) 51 arabinofuranosidase (Abf51A) of 57000Da. The substrate specificity of the Abf51A showed that it preferentially removed α1,2- and α1,3-linked arabinofuranose side chains from either arabinan or arabinoxylan, and hydrolysed α1,5-linked arabino-oligosaccharides, although at a much lower rate. The activity of Abf51A against arabinoxylan was similar to a GH62 arabinofuranosidase encoded by a P. cellulosa gene. Glu-194 and Glu-321 of Abf51A are conserved in GH51 enzymes, and it has been suggested that these amino acids comprise the key catalytic acid/base and nucleophile residues, respectively. To evaluate this hypothesis the biochemical properties of E194A and E321A mutants of Abf51A were evaluated. The data were consistent with the view that Glu-194 and Glu-321 comprise the key catalytic residues of Abf51A. These data, in conjunction with the results presented in the accompanying paper [Beylot, Emami, McKie, Gilbert and Pell (2001) Biochem. J. 358, 599–605], indicate that P. cellulosa expresses a membrane-bound GH51 arabinofuranosidase that plays a pivotal role in releasing arabinose from a range of polysaccharides and oligosaccharides.


Genetics ◽  
1980 ◽  
Vol 96 (4) ◽  
pp. 927-938
Author(s):  
David R Wilcox ◽  
Satya Prakash

ABSTRACT Twenty-six D. pseudoobscura strains isogenic for xanthine dehydrogenase alleles from Mesa Verde, Colorado, were tested for differences in the biochemical properties of different allelic forms of xanthine dehydrogenase. No significant differences in binding affinity (Km) or substrate specificity of the enzyme were found. Significant variation among strains, in activity (V  max) and among electromorphs, as well as among strains, in thermolability was found. For the few strains tested, the activity and thermolability differences were shown to co-segregate with the electrophoretic mobility of the variant allele.


2021 ◽  
Vol 22 (6) ◽  
pp. 3012
Author(s):  
James I. Mitchell-White ◽  
Thomas Stockner ◽  
Nicholas Holliday ◽  
Stephen J. Briddon ◽  
Ian D. Kerr

The five members of the mammalian G subfamily of ATP-binding cassette transporters differ greatly in their substrate specificity. Four members of the subfamily are important in lipid transport and the wide substrate specificity of one of the members, ABCG2, is of significance due to its role in multidrug resistance. To explore the origin of substrate selectivity in members 1, 2, 4, 5 and 8 of this subfamily, we have analysed the differences in conservation between members in a multiple sequence alignment of ABCG sequences from mammals. Mapping sets of residues with similar patterns of conservation onto the resolved 3D structure of ABCG2 reveals possible explanations for differences in function, via a connected network of residues from the cytoplasmic to transmembrane domains. In ABCG2, this network of residues may confer extra conformational flexibility, enabling it to transport a wider array of substrates.


Author(s):  
Xiaolong Liu ◽  
Meng Zhao ◽  
Xinjiong Fan ◽  
Yao Fu

One of the most important industrial applications of bacterial esterases is the production of optically pure compounds. However, the contradiction between the wide substrate specificity and high enantioselectivity of natural...


2005 ◽  
Vol 187 (20) ◽  
pp. 7072-7080 ◽  
Author(s):  
Rie Matsumi ◽  
Haruyuki Atomi ◽  
Tadayuki Imanaka

ABSTRACT We have performed the first biochemical characterization of a putative archaeal signal peptide peptidase (SppATk) from the hyperthermophilic archaeon Thermococcus kodakaraensis KOD1. SppATk, comprised of 334 residues, was much smaller than its counterpart from Escherichia coli (618 residues) and harbored a single predicted transmembrane domain near its N terminus. A truncated mutant protein without the N-terminal 54 amino acid residues (ΔN54SppATk) was found to be stable against autoproteolysis and was examined further. ΔN54SppATk exhibited peptidase activity towards fluorogenic peptide substrates and was found to be highly thermostable. Moreover, the enzyme displayed a remarkable stability and preference for alkaline pH, with optimal activity detected at pH 10. ΔN54SppATk displayed a Km of 240 ± 18 μM and a V max of 27.8 ± 0.7 μmol min−1 mg−1 towards Ala-Ala-Phe-4-methyl-coumaryl-7-amide at 80°C and pH 10. The substrate specificity of the enzyme was examined in detail with a FRETS peptide library. By analyzing the cleavage products with liquid chromatography-mass spectrometry, ΔN54SppATk was found to efficiently cleave peptides with a relatively small side chain at the P-1 position and a hydrophobic or aromatic residue at the P-3 position. The positively charged Arg residue was preferred at the P-4 position, while substrates with negatively charged residues at the P-2, P-3, or P-4 position were not cleaved. When predicted signal sequences from the T. kodakaraensis genome sequence were examined, we found that the substrate specificity of ΔN54SppATk was in good agreement with its presumed role as a signal peptide peptidase in this archaeon.


1969 ◽  
Vol 47 (2) ◽  
pp. 147-155 ◽  
Author(s):  
N. K. Ghosh ◽  
W. H. Fishman

Human placental alkaline phosphatase isoenzyme has been characterized in pregnancy serum by several biochemical criteria. The total serum alkaline phosphatase, its L-phenylalanine-sensitive moiety, heat inactivation, and the ratio of enzyme activity at pH 10.7 versus 9.8 (10.7/9.8 R) were measured during parturition and 59 weeks of pre- and post-natal periods. The extent of L-phenylalanine inhibition, heat stability, and 10.7/9.8 R of serum alkaline phosphatase progressively increased during gestation attaining maximum values during the delivery, after which they gradually declined. The electrophoretic behaviors of alkaline phosphatase isoenzymes of pregnancy sera were followed by starch- and Sephadex-gel electrophoreses. Alkaline phosphatase has been purified 300-fold from the placenta of the subject whose serum enzyme was investigated. The biochemical properties, including the electrophoretic behavior and neuraminidase sensitivity of heat-stable alkaline phosphastase in pregnancy sera at term, were comparable to those of purified placental alkaline phosphatase. The values for 10.7/9.8 R of the pregnancy sera were statistically different from those of sera from normal nonpregnant women. The results obtained in this study suggest that the enhanced level of pregnancy serum alkaline phosphatase is due to the enrichment of the circulation with an isoenzyme of placental origin.


2021 ◽  
Vol 22 (16) ◽  
pp. 9056
Author(s):  
Ada Połońska ◽  
Katarzyna Jasieniecka-Gazarkiewicz ◽  
Lingjie You ◽  
Xiahui Hao ◽  
Sylwia Klińska ◽  
...  

The search of the Phaeodactylum tricornutum genome database revealed the existence of six genes potentially encoding lysophospholipid acyltransferases. One of these genes, Phatr3_J20460, after introduction to yeast ale1 mutant disrupted in the LPCAT gene, produced a very active acyl-CoA:lysophosphatidylcholine (LPCAT) enzyme. Using in vitro assays applying different radioactive and non-radioactive substrates and microsomal fractions from such yeast, we have characterized the biochemical properties and substrate specificities of this PtLPCAT1. We have found that the substrate specificity of this enzyme indicates that it can completely supply phosphatidylcholine (PC) with all fatty acids connected with a biosynthetic pathway of very long-chain polyunsaturated fatty acids (VLC-PUFAs) used further for the desaturation process. Additionally, we have shown that biochemical properties of the PtLPCAT1 in comparison to plant LPCATs are in some cases similar (such as the dependency of its activity on pH value), differ moderately (such as in response to temperature changes), or express completely different properties (such as in reaction to calcium and magnesium ions or toward some acyl-CoA with 20C polyunsaturated fatty acids). Moreover, the obtained results suggest that cloned “Phatr3_J20460” gene can be useful in oilseeds plant engineering toward efficient production of VLC-PUFA as LPCAT it encodes can (contrary to plant LPCATs) introduce 20:4-CoA (n-3) to PC for further desaturation to 20:5 (EPA, eicosapentaenoic acid).


2019 ◽  
Vol 85 (18) ◽  
Author(s):  
Fang Zhao ◽  
Hai-Yan Cao ◽  
Long-Sheng Zhao ◽  
Yi Zhang ◽  
Chun-Yang Li ◽  
...  

ABSTRACTAs classified by the Carbohydrate-Active Enzymes (CAZy) database, enzymes in glycoside hydrolase (GH) family 10 (GH10) are all monospecific or bifunctional xylanases (except a tomatinase), and no endo-β-1,4-glucanase has been reported in the family. Here, we identifiedArcticibacterium luteifluviistationiscarboxymethyl cellulase (AlCMCase) as a GH10 endo-β-1,4-glucanase.AlCMCase originated from an Arctic marine bacterium,Arcticibacterium luteifluviistationisSM1504T. It shows low identity (<35%) with other GH10 xylanases. The gene encodingAlCMCase was overexpressed inEscherichia coli. Biochemical characterization showed that recombinantAlCMCase is a cold-adapted and salt-tolerant enzyme.AlCMCase hydrolyzes cello- and xylo-configured substrates via an endoaction mode. However, in comparison to its significant cellulase activity, the xylanase activity ofAlCMCase is negligible. Correspondingly,AlCMCase has remarkable binding capacity for cello-oligosaccharides but no obvious binding capacity for xylo-oligosaccharides.AlCMCase and its homologs are grouped into a branch separate from other GH10 xylanases in a phylogenetic tree, and two homologs also displayed the same substrate specificity asAlCMCase. These results suggest thatAlCMCase and its homologs form a novel subfamily of GH10 enzymes that have robust endo-β-1,4-glucanase activity. In addition, given the cold-adapted and salt-tolerant characters ofAlCMCase, it may be a candidate biocatalyst under certain industrial conditions, such as low temperature or high salinity.IMPORTANCECellulase and xylanase have been widely used in the textile, pulp and paper, animal feed, and food-processing industries. Exploring novel cellulases and xylanases for biocatalysts continues to be a hot issue. Enzymes derived from the polar seas might have novel hydrolysis patterns, substrate specificities, or extremophilic properties that have great potential for both fundamental research and industrial applications. Here, we identified a novel cold-adapted and salt-tolerant endo-β-1,4-glucanase,AlCMCase, from an Arctic marine bacterium. It may be useful in certain industrial processes, such as under low temperature or high salinity. Moreover,AlCMCase is a bifunctional representative of glycoside hydrolase (GH) family 10 that preferentially hydrolyzes β-1,4-glucans. With its homologs, it represents a new subfamily in this family. Thus, this study sheds new light on the substrate specificity of GH10.


1999 ◽  
Vol 179 (2) ◽  
pp. 385-392 ◽  
Author(s):  
Byung-Chul Oh ◽  
Hyung-Kwoun Kim ◽  
Jung-Kee Lee ◽  
Sun-Chul Kang ◽  
Tae-Kwang Oh

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