scholarly journals Cloning, Expression, and Characterization of a New PL25 Family Ulvan Lyase from Marine Bacterium Alteromonas sp. A321

Marine Drugs ◽  
2019 ◽  
Vol 17 (10) ◽  
pp. 568 ◽  
Author(s):  
Jian Gao ◽  
Chunying Du ◽  
Yongzhou Chi ◽  
Siqi Zuo ◽  
Han Ye ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Molecular Weight ◽  
Amino Acid ◽  
Marine Bacterium ◽  
Apparent Molecular Weight ◽  
Maximal Activity ◽  
Amino Acid Residues ◽  
Polysaccharide Lyase ◽  
Sequence Identity

Ulvan lyases can degrade ulvan to oligosaccharides with potent biological activity. A new ulvan lyase gene, ALT3695, was identified in Alteromonas sp. A321. Soluble expression of ALT3695 was achieved in Escherichia coli BL21 (DE3). The 1314-bp gene encoded a protein with 437 amino acid residues. The amino acid sequence of ALT3695 exhibited low sequence identity with polysaccharide lyase family 25 (PL25) ulvan lyases from Pseudoalteromonas sp. PLSV (64.14% identity), Alteromonas sp. LOR (62.68% identity), and Nonlabens ulvanivorans PLR (57.37% identity). Recombinant ALT3695 was purified and the apparent molecular weight was about 53 kDa, which is different from that of other polysaccharide-degrading enzymes identified in Alteromonas sp. A321. ALT3695 exhibited maximal activity in 50 mM Tris-HCl buffer at pH 8.0 and 50 °C. ALT3695 was relatively thermostable, as 90% activity was observed after incubation at 40 °C for 3 h. The Km and Vmax values of ALT3695 towards ulvan were 0.43 mg·mL−1 and 0.11 μmol·min−1·mL−1, respectively. ESI-MS analysis showed that enzymatic products were mainly disaccharides and tetrasaccharides. This study reports a new PL25 family ulvan lyase, ALT3695, with properties that suggest its great potential for the preparation of ulvan oligosaccharides.

scholarly journals Purification of a high-molecular-weight somatoliberin (growth-hormone-releasing factor) from pig hypothalami

1983 ◽  
Vol 209 (3) ◽  
pp. 643-651 ◽  
Author(s):  
J E C Sykes ◽  
P J Lowry
Keyword(s):  
Molecular Weight ◽  
Growth Hormone ◽  
Amino Acid ◽  
Response Curve ◽  
Gel Filtration ◽  
Apparent Molecular Weight ◽  
Amino Acid Residues ◽  
Growth Hormone Releasing Factor

Preliminary observations [Sykes & Lowry (1980) J. Endocrinol. 85, 42P-43P] had suggested that the major hypothalamic somatoliberin (growth-hormone-releasing factor) was a larger peptide than the other characterized hypothalamic factors, with an elution position on Sephadex G-50 between those of neurophysin and corticotropin. The present paper reports the isolation and preliminary characterization of pig hypothalamic somatoliberin. Acid extracts of pig stalk median eminence were purified by gel filtration and preparative and analytical high-pressure liquid chromatography to yield a preparation that was specific in the release of somatotropin (growth hormone) in vitro, giving a steep dose-response curve at doses in the range 0.20-3.0 ng. Amino acid analysis revealed a non-cysteine-containing peptide with a high number of glutamate (or glutamine) and aspartate (or asparagine) residues. The peptide had about 56-57 amino acid residues and an apparent molecular weight of 6400, in keeping with its elution position on a column of Sephadex G-50.

scholarly journals Cloning of the Novel Gene Encoding β-Agarase C from a Marine Bacterium, Vibrio sp. Strain PO-303, and Characterization of the Gene Product

2006 ◽  
Vol 72 (9) ◽  
pp. 6399-6401 ◽  
Author(s):  
Jinhua Dong ◽  
Shinnosuke Hashikawa ◽  
Takafumi Konishi ◽  
Yutaka Tamaru ◽  
Toshiyoshi Araki
Keyword(s):  
Amino Acid ◽  
Gene Product ◽  
Glycoside Hydrolase ◽  
Marine Bacterium ◽  
Glycoside Hydrolase Family ◽  
The Novel ◽  
Amino Acid Residues ◽  
Gene Encoding ◽  
Hydrolase Family

ABSTRACT The β-agarase C gene (agaC) of a marine bacterium, Vibrio sp. strain PO-303, consisted of 1,437 bp encoding 478 amino acid residues. β-Agarase C was identified as the first β-agarase that cannot hydrolyze neoagarooctaose and smaller neoagarooligosaccharides and was assigned to a novel glycoside hydrolase family.

scholarly journals The 8-amino-7-oxopelargonate synthase from Bacillus sphaericus. Purification and preliminary characterization of the cloned enzyme overproduced in Escherichia coli

1992 ◽  
Vol 283 (2) ◽  
pp. 327-331 ◽  
Author(s):  
O Ploux ◽  
A Marquet
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Absorption Band ◽  
Specific Activity ◽  
Bacillus Sphaericus ◽  
Complete Agreement ◽  
Amino Acid Residues ◽  
Characteristic Absorption Band ◽  
Preliminary Characterization

The 8-amino-7-oxopelargonate synthase [6-carboxyhexanoyl-CoA:L-alanine carboxyhexanoyltransferase (decarboxylating); EC 2.3.1.47] from Bacillus sphaericus involved in biotin biosynthesis was purified from an Escherichia coli overproducing strain. The purification afforded an electrophoretically homogeneous enzyme with a specific activity of 0.67 unit/mg. The purified enzyme is a monomer of 41 kDa. N-Terminal sequencing of the first 14 amino acid residues showed complete agreement with the predicted sequence from the bioF gene. The pure enzyme showed the characteristic absorption band (425 nm) of pyridoxal 5′-phosphate-dependent enzymes. Furthermore, the holoenzyme was resolved during an affinity step yielding the inactive apoenzyme, which recovered activity and the 425 nm-absorption band on dialysis against pyridoxal 5′-phosphate. Km values for L-alanine and pimeloyl-CoA were respectively 3 mM and 1 microM.

scholarly journals Genetic and mutational characterization of the small alarmone synthetase gene relV of Vibrio cholerae

Microbiology ◽  
2014 ◽  
Vol 160 (9) ◽  
pp. 1855-1866 ◽  
Author(s):  
Shreya Dasgupta ◽  
Pallabi Basu ◽  
Ritesh Ranjan Pal ◽  
Satyabrata Bag ◽  
Rupak K. Bhadra
Keyword(s):  
Escherichia Coli ◽  
Amino Acid ◽  
Small Molecules ◽  
Vibrio Cholerae ◽  
Stringent Response ◽  
Synthetase Activity ◽  
Gram Negative Bacteria ◽  
Amino Acid Residues ◽  
Gram Negative

In Vibrio cholerae, the causative agent of cholera, products of three genes, relA, spoT and relV, govern nutritional stress related stringent response (SR). SR in bacteria is critically regulated by two intracellular small molecules, guanosine 3′-diphosphate 5′-triphosphate (pppGpp) and guanosine 3′,5′-bis(diphosphate) (ppGpp), collectively called (p)ppGpp or alarmone. Evolution of relV is unique in V. cholerae because other Gram-negative bacteria carry only relA and spoT genes. Recent reports suggest that RelV is needed for pathogenesis. RelV carries a single (p)ppGpp synthetase or RelA-SpoT domain (SYNTH/RSD) and belongs to the small alarmone synthetase (SAS) family of proteins. Here, we report extensive functional characterizations of the relV gene by constructing several deletion and site-directed mutants followed by their controlled expression in (p)ppGpp0 cells of Escherichia coli or V. cholerae. Substitution analysis indicated that the amino acid residues K107, D129, R132, L150 and E188 of the RSD region of RelV are essential for its activity. While K107, D129 and E188 are highly conserved in RelA and SAS proteins, L150 appears to be conserved in the latter group of enzymes, and the R132 residue was found to be unique in RelV. Extensive progressive deletion analysis indicated that the amino acid residues at positions 59 and 248 of the RelV protein are the functional N- and C-terminal boundaries, respectively. Since the minimal functional length of RelV was found to be 189 aa, which includes the 94 aa long RSD region, it seems that the flanking residues of the RSD are also important for maintaining the (p)ppGpp synthetase activity.

scholarly journals Isolation and Characterization of a Novel Cold-Active, Halotolerant Endoxylanase from Echinicola rosea Sp. Nov. JL3085T

Marine Drugs ◽  
2020 ◽  
Vol 18 (5) ◽  
pp. 245
Author(s):  
Jianlong He ◽  
Le Liu ◽  
Xiaoyan Liu ◽  
Kai Tang
Keyword(s):  
Amino Acid ◽  
Marine Bacterium ◽  
Maximum Velocity ◽  
Maximum Activity ◽  
Glycoside Hydrolases ◽  
Amino Acid Residues ◽  
Xylanase Gene ◽  
Isolation And Characterization ◽  
Cold Active

We cloned a xylanase gene (xynT) from marine bacterium Echinicola rosea sp. nov. JL3085T and recombinantly expressed it in Escherichia coli BL21. This gene encoded a polypeptide with 379 amino acid residues and a molecular weight of ~43 kDa. Its amino acid sequence shared 45.3% similarity with an endoxylanase from Cellvibrio mixtus that belongs to glycoside hydrolases family 10 (GH10). The XynT showed maximum activity at 40 °C and pH 7.0, and a maximum velocity of 62 μmoL min−1 mg−1. The XynT retained its maximum activity by more than 69%, 51%, and 26% at 10 °C, 5 °C, and 0 °C, respectively. It also exhibited the highest activity of 135% in the presence of 4 M NaCl and retained 76% of its activity after 24 h incubation with 4 M NaCl. This novel xylanase, XynT, is a cold-active and halotolerant enzyme that may have promising applications in drug, food, feed, and bioremediation industries.

scholarly journals Characterization of gastric mucoproteins isolated by equilibrium density-gradient centrifugation in caesium chloride

1974 ◽  
Vol 141 (3) ◽  
pp. 633-639 ◽  
Author(s):  
Bryan J. Starkey ◽  
David Snary ◽  
Adrian Allen
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Gradient Centrifugation ◽  
Gel Filtration ◽  
Equilibrium Density ◽  
Amino Acid Residues ◽  
Gastric Mucus ◽  
Terminal Amino Acid ◽  
Terminal Amino

1. The mucoprotein from pig gastric mucus has been purified by equilibrium centrifugation in a CsCl gradient. 2. This procedure removes the non-covalently bound protein, which is closely associated with the mucoprotein and not easily removed from it by gel filtration. 3. The purified mucoprotein is separable by gel filtration into a high-molecular-weight mucoprotein A (mol.wt. 2.3×106) and a low-molecular-weight mucoprotein B/C (mol.wt. 1.15×106). 4. These two mucoproteins have the same chemical analysis namely fucose 11.3%, galactose 26%, glucosamine 19.5%, galactosamine 8.3% and protein 13.6%. 5. Mucoprotein A contains 3.1% ester sulphate. 6. These mucoproteins are isolated without enzymic digestion and have a higher protein content than the blood-group-substance mucoproteins from proteolytic digestion of gastric mucus. Detailed amino acid analysis shows that the extra protein in the non-enzymically digested material is composed of amino acids other than serine and threonine. 7. Mucoproteins A and B/C contain respectively 130 and 9 half-cystine residues per molecule of which about 78 and 6 residues are involved in disulphide linkages. 8. Cleavage of these disulphide linkages by mercaptoethanol splits both mucoproteins into four equally sized subunits of mol.wt. 5.2×105for mucoprotein A and 2.8×104for mucoprotein B/C. 9. The sole N-terminal amino acid of mucoprotein A is aspartic acid, whereas mucoprotein B/C has several different N-terminal amino acid residues.

scholarly journals Purification and Characterization of A New Cold-Adapted and Thermo-Tolerant Chitosanase from Marine Bacterium Pseudoalteromonas sp. SY39

Molecules ◽  
2019 ◽  
Vol 24 (1) ◽  
pp. 183 ◽  
Author(s):  
Yu Zhou ◽  
Xuehong Chen ◽  
Xiao Li ◽  
Yantao Han ◽  
Yanan Wang ◽  
...  
Keyword(s):  
Enzymatic Degradation ◽  
Marine Bacterium ◽  
Degradation Products ◽  
Biological Activities ◽  
Apparent Molecular Weight ◽  
Maximal Activity ◽  
Purification And Characterization ◽  
Cold Adapted ◽  
Total Product

Chitosanases play an important role in chitosan degradation, forming enzymatic degradation products with several biological activities. Although many chitosanases have been discovered and studied, the enzymes with special characteristics are still rather rare. In this study, a new chitosanase, CsnM, with an apparent molecular weight of 28 kDa was purified from the marine bacterium Pseudoalteromonas sp. SY39. CsnM is a cold-adapted enzyme, which shows highest activity at 40 °C and exhibits 30.6% and 49.4% of its maximal activity at 10 and 15 °C, respectively. CsnM is also a thermo-tolerant enzyme that recovers 95.2%, 89.1% and 88.1% of its initial activity after boiling for 5, 10 and 20 min, respectively. Additionally, CsnM is an endo-type chitosanase that yields chitodisaccharide as the main product (69.9% of the total product). It’s cold-adaptation, thermo-tolerance and high chitodisaccharide yield make CsnM a superior candidate for biotechnological application to produce chitooligosaccharides.

scholarly journals Cloning of a Novel Gene Encoding β-1,3-Xylosidase from a Marine Bacterium, Vibrio sp. Strain XY-214, and Characterization of the Gene Product

2007 ◽  
Vol 74 (1) ◽  
pp. 305-308 ◽  
Author(s):  
Yoshiaki Umemoto ◽  
Ryosuke Onishi ◽  
Toshiyoshi Araki
Keyword(s):  
Escherichia Coli ◽  
Amino Acids ◽  
Molecular Weight ◽  
Nucleotide Sequence ◽  
Gene Product ◽  
Marine Bacterium ◽  
Gene Encoding ◽  
Novel Gene ◽  
Sequence Encoding

ABSTRACT The β-1,3-xylosidase gene (xloA) of Vibrio sp. strain XY-214 was cloned and expressed in Escherichia coli. The xloA gene consisted of a 1,608-bp nucleotide sequence encoding a protein of 535 amino acids with a predicted molecular weight of 60,835. The recombinant β-1,3-xylosidase hydrolyzed β-1,3-xylooligosaccharides to d-xylose as a final product.

scholarly journals Biochemical Characterization of a Prokaryotic Phenylalanine Ammonia Lyase

2005 ◽  
Vol 187 (12) ◽  
pp. 4286-4289 ◽  
Author(s):  
Longkuan Xiang ◽  
Bradley S. Moore
Keyword(s):  
Amino Acid ◽  
Cinnamic Acid ◽  
Marine Bacterium ◽  
Phenylalanine Ammonia Lyase ◽  
Biochemical Characterization ◽  
The Novel ◽  
Amino Acid Residues ◽  
Primary Amino ◽  
Biochemical Features

ABSTRACT The committed biosynthetic reaction to benzoyl-coenzyme A in the marine bacterium “Streptomyces maritimus” is carried out by the novel prokaryotic phenylalanine ammonia lyase (PAL) EncP, which converts the primary amino acid l-phenylalanine to trans-cinnamic acid. Recombinant EncP is specific for l-phenylalanine and shares many biochemical features with eukaryotic PALs, which are substantially larger proteins by ∼200 amino acid residues.

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