scholarly journals Expression and protease characterization of a conserved protein YgjD in Vibrio harveyi

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9061
Author(s):  
Yayuan Zhang ◽  
Jixiang Chen ◽  
Yonggang Wang ◽  
Yanlin Li ◽  
Wenhong Rui ◽  
...  

The glycopeptidase GCP and its homologue proteins are conserved and essential for survival of bacteria. The ygjD gene (Glycopeptidase homologue) was cloned from Vibrio harveyi strain SF-1. The gene consisted of 1,017 bp, which encodes a 338 amino acid polypeptide. The nucleotide sequence similarity of the ygjD gene with that of V. harveyi FDAARGOS 107 was 95%. The ygjD gene also showed similarities of 68%, 67% and 50% with those of Salmonella enterica, Escherichia coli and Bacillus cereus. The ygjD gene was expressed in E. coli BL21 (DE3) and the recombinant YgjD was purified by Ni2+ affinity chromatography column. The purified YgjD showed a specific 37 kDa band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and exhibited protease activities of 59,000 units/mg, 53,700 units/mg and 8,100 units/mg, respectively, on N-Acetyl-L-tyrosine ethyl ester monohydrate (ATEE), N-Benzoyl-L-tyrosine ethyl ester (BTEE) and N-Benzoyl-DL-arginine-4-nitroanilide hydrochloride (BAPNA) substrates. When the conserved amino acids of His111, Glu113 and His115 in the YgjD were replaced with alanine, respectively, the protease activities of the mutants were partly decreased. The two conserved His111 and His115 of YgjD were mutated and the protein lost the protease activity, which implied that the two amino acid played very important roles in maintaining its protease activity. The addition of the purified YgjD to the culture medium of V. harveyi strain SF-1 can effectively promote the bacteria growth. These results indicated that the protease activities may be involved in the survival of bacteria.

2002 ◽  
Vol 184 (23) ◽  
pp. 6544-6550 ◽  
Author(s):  
Florence K. Gleason ◽  
Neil E. Olszewski

ABSTRACT The gene for ribonucleotide reductase from Anabaena sp. strain PCC 7120 was identified and expressed in Escherichia coli. This gene codes for a 1,172-amino-acid protein that contains a 407-amino-acid intein. The intein splices itself from the protein when it is expressed in E. coli, yielding an active ribonucleotide reductase of 765 residues. The mature enzyme was purified to homogeneity from E. coli extracts. Anabaena ribonucleotide reductase is a monomer with a molecular weight of approximately 88,000, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and Superose 12 column chromatography. The enzyme reduces ribonucleotides at the triphosphate level and requires a divalent cation and a deoxyribonucleoside triphosphate effector. The enzyme is absolutely dependent on the addition of the cofactor, 5′-adenosylcobalamin. These properties are characteristic of the class II-type reductases. The cyanobacterial enzyme has limited sequence homology to other class II reductases; the greatest similarity (38%) is to the reductase from Lactobacillus leichmannii. In contrast, the Anabaena reductase shows over 90% sequence similarity to putative reductases found in genome sequences of other cyanobacteria, such as Nostoc punctiforme, Synechococcus sp. strain WH8102, and Prochlorococcus marinus MED4, suggesting that the cyanobacterial reductases form a closely related subset of the class II enzymes.


Toxins ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 518
Author(s):  
Honghai Zhang ◽  
Yunpeng Zhang ◽  
Tie Yin ◽  
Jing Wang ◽  
Xiaolin Zhang

Ochratoxin A (OTA) is a well-known, natural contaminant in foods and feeds because of its toxic effects, such as nephrotoxicity in various animals. Recent studies have revealed that Alcaligenes faecalis could generate enzymes to efficiently degrade OTA to ochratoxin α (OTα) in vitro. In an effort to obtain the OTA degrading mechanism, we purified and identified a novel degrading enzyme, N-acyl-L-amino acid amidohydrolase (AfOTase), from A. faecalis DSM 16503 via mass spectrometry. The same gene of the enzyme was also encountered in other A. faecalis strains. AfOTase belongs to peptidase family M20 and contains metal ions at the active site. In this study, recombination AfOTase was expressed and characterized in Escherichia coli. The molecular mass of recombinant rAfOTase was approximately 47.0 kDa, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The enzyme exhibited a wide temperature range (30–70 °C) and pH adaptation (4.5–9.0) and the optimal temperature and pH were 50 °C and 6.5, respectively.


Blood ◽  
1989 ◽  
Vol 73 (5) ◽  
pp. 1202-1206 ◽  
Author(s):  
MG Bolyard ◽  
ST Lord

Abstract The human fibrinogen B beta chain was expressed in Escherichia coli to study the functions of fibrinogen associated with this subunit. Recombinant B beta chains were expressed at 100 ng/mL in an IPTG- dependent manner. A first cistron sequence, inserted into the expression vector 5′ to the B beta chain cDNA, was required to express the protein. Recombinant B beta chains were expressed within five minutes after induction with IPTG and were soluble in physiologic buffers. The recombinant B beta chains migrated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) at a rate identical to B beta chains from fibrinogen treated with N-glycanase. Recombinant B beta chains were cleaved by thrombin, as demonstrated by the loss of cross-reactivity with a monoclonal antibody (MoAb) specific for the undigested B beta 1–42 fragment. The levels of expression of the B beta chain were much lower than those reported previously for the gamma chain of fibrinogen expressed in a similar vector in E coli. However, these levels are sufficient to allow further characterization of this fibrinogen subunit.


Blood ◽  
1992 ◽  
Vol 79 (5) ◽  
pp. 1206-1212 ◽  
Author(s):  
RJ Olds ◽  
DA Lane ◽  
R Caso ◽  
M Panico ◽  
HR Morris ◽  
...  

Abstract Antithrombin III (AT) is a major plasma serine protease inhibitor and a member of the serpin family of proteins. We have characterized the molecular and genetic basis of AT Budapest, an inherited variant of AT that is associated with thrombotic disease in affected family members. A single amino acid substitution, 429Pro to Leu, was identified, occurring in a region of the molecule that is highly conserved in members of the serpin family. Two forms of variant protein were present in approximately equal amounts in the plasma of the propositus, who is homozygous for the mutation. One form, which had apparently normal Mr, bound heparin strongly and retained some residual thrombin inhibitory activity. The other form had only weak heparin affinity and no antiproteinase activity, and had slightly decreased mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions; this normalized in the presence of a reducing agent, suggesting it was caused by a change in conformation. Additional support for a difference in conformation of the two forms of variant was provided by the finding that the fraction that bound heparin- Sepharose was recognized by a monoclonal antibody raised against normal AT, whereas the weak-affinity fraction was not.


1987 ◽  
Vol 65 (10) ◽  
pp. 899-908 ◽  
Author(s):  
F. Moranelli ◽  
M. Yaguchi ◽  
G. B. Calleja ◽  
A. Nasim

The extracellular α-amylase activity of the yeast Schwanniomyces alluvius has been purified by anion-exchange chromatography on DEAE-cellulose and gel-filtration chromatography on Sephadex G-100. Sodium dodecyl sulfate – polyacrylamide gel electrophoresis (SDS–PAGE) and N-terminal amino acid analysis of the purified sample indicated that the enzyme preparation was homogeneous. The enzyme is a glycoprotein having a molecular mass of 52 kilodaltons (kDa) estimated by SDS–PAGE and 39 kDa by gel filtration on Sephadex G-100. Chromatofocusing shows that it is an acidic protein. It is resistant to trypsin but sensitive to proteinase K. Its activity is inhibited by the divalent cation chelators EDTA and EGTA and it is insensitive to sulfhydryl-blocking agents. Exogenous divalent cations are inhibitory as are high concentrations of monovalent salts. The enzyme has a pH optimum between 3.75 and 5.5 and displays maximum stability in the pH range of 4.0–7.0. Under the conditions tested, the activity is maximal between 45 and 50 °C and is very thermolabile. Analysis of its amino acid composition supports its acidic nature.


Blood ◽  
1992 ◽  
Vol 79 (5) ◽  
pp. 1206-1212 ◽  
Author(s):  
RJ Olds ◽  
DA Lane ◽  
R Caso ◽  
M Panico ◽  
HR Morris ◽  
...  

Antithrombin III (AT) is a major plasma serine protease inhibitor and a member of the serpin family of proteins. We have characterized the molecular and genetic basis of AT Budapest, an inherited variant of AT that is associated with thrombotic disease in affected family members. A single amino acid substitution, 429Pro to Leu, was identified, occurring in a region of the molecule that is highly conserved in members of the serpin family. Two forms of variant protein were present in approximately equal amounts in the plasma of the propositus, who is homozygous for the mutation. One form, which had apparently normal Mr, bound heparin strongly and retained some residual thrombin inhibitory activity. The other form had only weak heparin affinity and no antiproteinase activity, and had slightly decreased mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) under nonreducing conditions; this normalized in the presence of a reducing agent, suggesting it was caused by a change in conformation. Additional support for a difference in conformation of the two forms of variant was provided by the finding that the fraction that bound heparin- Sepharose was recognized by a monoclonal antibody raised against normal AT, whereas the weak-affinity fraction was not.


1999 ◽  
Vol 65 (9) ◽  
pp. 4028-4031 ◽  
Author(s):  
Takeshi Shibasaki ◽  
Hideo Mori ◽  
Shigeru Chiba ◽  
Akio Ozaki

ABSTRACT Microbial proline 4-hydroxylases, which hydroxylate freel-proline totrans-4-hydroxy-l-proline, were screened in order to establish an industrial system for biotransformation of l-proline totrans-4-hydroxy-l-proline. Enzyme activities were detected in eight strains, including strains ofDactylosporangium spp. and Amycolatopsis spp. The Dactylosporangium sp. strain RH1 enzyme was partially purified 3,300-fold and was estimated to be a monomer polypeptide with an apparent molecular mass of 31 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Degenerate primers based on the N-terminal amino acid sequence of the 31-kDa polypeptide were synthesized in order to amplify the corresponding 71-bp DNA fragment. A 5.5-kbp DNA fragment was isolated by using the 71-bp fragment labeled with digoxigenin as a probe for a genomic library ofDactylosporangium sp. strain RH1 constructed inEscherichia coli. One of the open reading frames found in the cloned DNA, which encoded a 272-amino-acid polypeptide (molecular mass, 29,715 daltons), was thought to be a proline 4-hydroxylase gene. The gene was expressed in E. coli as a fused protein with the N-terminal 34 amino acids of the β-galactosidase α-fragment. The E. coli recombinant exhibited proline 4-hydroxylase activity that was 13.6-fold higher than the activity in the original strain, Dactylosporangium sp. strain RH1. No homology was detected with other 2-oxoglutarate-dependent dioxygenases when databases were searched; however, the histidine motif conserved in 2-oxoglutarate-dependent dioxygenases was found in the gene.


1993 ◽  
Vol 265 (5) ◽  
pp. G894-G902 ◽  
Author(s):  
D. D. Stump ◽  
S. L. Zhou ◽  
P. D. Berk

A relationship between plasma membrane fatty acid binding protein (FABPpm), a putative membrane transporter for long-chain fatty acids, and the mitochondrial isoform of aspartate aminotransferase (m-AspAT) has been reported. Accordingly, we have compared the chemical and immunological properties of rat liver m-AspAT with those of rat liver FABPpm isolated by two procedures: 1) detergent solubilization of the membranes followed by purification via fatty acid affinity chromatography (FABP-1) or 2) salt extraction of the membranes and subsequent purification by high-performance liquid chromatography (HPLC; FABP-2). Comparison of the three protein preparations revealed no differences with respect to NH2-terminal amino acid sequence, amino acid composition, peptides from tryptic digests, AspAT enzymatic activity, isoelectric point, mobility on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), retention on five different HPLC columns, and immunoprecipitation and immunoblotting of SDS-PAGE separated proteins with polyclonal antisera. Examination of the proteins by nondenaturing PAGE showed a consistent second band in FABP-1 and FABP-2 not always present in m-AspAT. However, whenever present, this band was immunoreactive with antibodies to both m-AspAT and FABP-1. Hence, FABP-1 and FABP-2 are indistinguishable from one another. They are also at least closely related, if not identical, to m-AspAT.


Genome ◽  
2006 ◽  
Vol 49 (2) ◽  
pp. 181-189 ◽  
Author(s):  
H Q Wang ◽  
X Y Zhang

High-molecular-weight glutenin subunits (HMW-GSs) play an important role in the breadmaking quality of wheat flour. In China, cultivars such as Triticum aestivum 'Xiaoyan No. 6' carrying the 1Bx14 and 1By15 glutenin subunits usually have attributes that result in high-quality bread and noodles. HMW-GS 1Bx14 and 1By15 were isolated by preparative sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and used as an antigen to immunize BALB/c mice. A resulting monoclonal antibody belonging to the IgG1 subclass was shown to bind to all HMW-GSs of Triticum aestivum cultivars, but did not bind to other storage proteins of wheat seeds in a Western blot analysis. After screening a complementary DNA expression library from immature seeds of 'Xiaoyan No. 6' using the monoclonal antibody, the HMW-GS 1By15 gene was isolated and fully sequenced. The deduced amino acid sequence showed an extra stretch of 15 amino acid repeats consisting of a hexapeptide and a nonapeptide in the repetitive domain of this y-type HMW subunit. Bacterial expression of a modified 1By15 gene, in which the coding sequence for the signal peptide was removed and a BamHI site eliminated, gave rise to a protein with mobility identical to that of HMW-GSs extracted from seeds of 'Xiaoyan No. 6' via SDS-PAGE. This approach for isolating genes using specific monoclonal antibody against HMW-GS genes is a good alternative to the extensively used polymerase chain reaction (PCR) technology based on sequence homology of HMW-GSs in wheat and its relatives.Key words: wheat, HMW-GS, monoclonal antibody, immunoscreen.


2002 ◽  
Vol 184 (21) ◽  
pp. 5955-5965 ◽  
Author(s):  
Thomas Hansen ◽  
Bianca Reichstein ◽  
Roland Schmid ◽  
Peter Schönheit

ABSTRACT An ATP-dependent glucokinase of the hyperthermophilic aerobic crenarchaeon Aeropyrum pernix was purified 230-fold to homogeneity. The enzyme is a monomeric protein with an apparent molecular mass of about 36 kDa. The apparent Km values for ATP and glucose (at 90°C and pH 6.2) were 0.42 and 0.044 mM, respectively; the apparent V max was about 35 U/mg. The enzyme was specific for ATP as a phosphoryl donor, but showed a broad spectrum for phosphoryl acceptors: in addition to glucose, which showed the highest catalytic efficiency (k cat/Km ), the enzyme also phosphorylates glucosamin, fructose, mannose, and 2-deoxyglucose. Divalent cations were required for maximal activity: Mg2+, which was most effective, could partially be replaced with Co2+, Mn2+, and Ni2+. The enzyme had a temperature optimum of at least 100°C and showed significant thermostability up to 100°C. The coding function of open reading frame (ORF) APE2091 (Y. Kawarabayasi, Y. Hino, H. Horikawa, S. Yamazaki, Y. Haikawa, K. Jin-no, M. Takahashi, M. Sekine, S. Baba, A. Ankai, H. Kosugi, A. Hosoyama, S. Fukui, Y. Nagai, K. Nishijima, H. Nakazawa, M. Takamiya, S. Masuda, T. Funahashi, T. Tanaka, Y. Kudoh, J. Yamazaki, N. Kushida, A. Oguchi, and H. Kikuchi, DNA Res. 6:83-101, 145-152, 1999), previously annotated as gene glk, coding for ATP-glucokinase of A. pernix, was proved by functional expression in Escherichia coli. The purified recombinant ATP-dependent glucokinase showed a 5-kDa higher molecular mass on sodium dodecyl sulfate-polyacrylamide gel electrophoresis, but almost identical kinetic and thermostability properties in comparison to the native enzyme purified from A. pernix. N-terminal amino acid sequence of the native enzyme revealed that the translation start codon is a GTG 171 bp downstream of the annotated start codon of ORF APE2091. The amino acid sequence deduced from the truncated ORF APE2091 revealed sequence similarity to members of the ROK family, which comprise bacterial sugar kinases and transcriptional repressors. This is the first report of the characterization of an ATP-dependent glucokinase from the domain of Archaea, which differs from its bacterial counterparts by its monomeric structure and its broad specificity for hexoses.


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