scholarly journals Characterization of a Bifidobacterium longum BORI Dipeptidase Belonging to the U34 Family

2007 ◽  
Vol 73 (17) ◽  
pp. 5598-5606 ◽  
Author(s):  
Jeong Min Seo ◽  
Geun Eog Ji ◽  
Sang Hee Cho ◽  
Myung Soo Park ◽  
Hyong Joo Lee

ABSTRACT A dipeptidase was purified from a cell extract of Bifidobacterium longum BORI by ammonium sulfate precipitation and chromatography on DEAE-cellulose and Q-Sepharose columns. The purified dipeptidase had a molecular mass of about 49 kDa and was optimally active at pH 8.0 and 50°C. The enzyme was a strict dipeptidase, being capable of hydrolyzing a range of dipeptides but not tri- and tetrapeptides, p-nitroanilide derivatives of amino acids, or N- or C-terminus-blocked dipeptides. A search of the amino acid sequence of an internal tryptic fragment against protein sequences deduced from the total genome sequence of B. longum NCC2705 revealed that it was identical to an internal sequence of the dipeptidase gene (pepD), which comprised 1,602 nucleotides encoding 533 amino acids with a molecular mass of 60 kDa, and thereby differed considerably from the 49-kDa mass of the purified dipeptidase. To understand this discrepancy, pepD was cloned into an Escherichia coli expression vector (pBAD-TOPO derivative) to generate the recombinant plasmids pBAD-pepD and pBAD-pepD-His (note that His in the plasmid designation stands for a polyhistidine coding region). Both plasmids were successfully expressed in E. coli, and the recombinant protein PepD-His was purified using nickel-chelating affinity chromatography and reconfirmed by internal amino acid sequencing. The PepD sequence was highly homologous to those of the U34 family of peptidases, suggesting that the B. longum BORI dipeptidase is a type of cysteine-type N-terminal nucleophile hydrolase and has a β-hairpin motif similar to that of penicillin V acylase, which is activated by autoproteolytic processing.

1984 ◽  
Vol 62 (5) ◽  
pp. 276-279 ◽  
Author(s):  
C. H. Lin ◽  
W. Chung ◽  
K. P. Strickland ◽  
A. J. Hudson

An isozyme of S-adenosylmethionine synthetase has been purified to homogeneity by ammonium sulfate fractionation, DEAE-cellulose column chromatography, and gel filtration on a Sephadex G-200 column. The purified enzyme is very unstable and has a molecular weight of 120 000 consisting of two identical subunits. Amino acid analysis on the purified enzyme showed glycine, glutamate, and aspartate to be the most abundant and the aromatic amino acids to be the least abundant. It possesses tripolyphosphatase activity which can be stimulated five to six times by S-adenosylmethionine (20–40 μM). The findings support the conclusion that an enzyme-bound tripolyphosphate is an obligatory intermediate in the enzymatic synthesis of S-adenosylmethionine from ATP and methionine.


2002 ◽  
Vol 184 (8) ◽  
pp. 2225-2234 ◽  
Author(s):  
Jason P. Folster ◽  
Terry D. Connell

ABSTRACT ChiA, an 88-kDa endochitinase encoded by the chiA gene of the gram-negative enteropathogen Vibrio cholerae, is secreted via the eps-encoded main terminal branch of the general secretory pathway (GSP), a mechanism which also transports cholera toxin. To localize the extracellular transport signal of ChiA that initiates transport of the protein through the GSP, a chimera comprised of ChiA fused at the N terminus with the maltose-binding protein (MalE) of Escherichia coli and fused at the C terminus with a 13-amino-acid epitope tag (E-tag) was expressed in strain 569B(chiA::Kanr), a chiA-deficient but secretion-competent mutant of V. cholerae. Fractionation studies revealed that blockage of the natural N terminus and C terminus of ChiA did not prevent secretion of the MalE-ChiA-E-tag chimera. To locate the amino acid sequences which encoded the transport signal, a series of truncations of ChiA were engineered. Secretion of the mutant polypeptides was curtailed only when ChiA was deleted from the N terminus beyond amino acid position 75 or from the C terminus beyond amino acid 555. A mutant ChiA comprised of only those amino acids was secreted by wild-type V. cholerae but not by an epsD mutant, establishing that amino acids 75 to 555 independently harbored sufficient structural information to promote secretion by the GSP of V. cholerae. Cys77 and Cys537, two cysteines located just within the termini of ChiA(75-555), were not required for secretion, indicating that those residues were not essential for maintaining the functional activity of the ChiA extracellular transport signal.


Development ◽  
1970 ◽  
Vol 24 (1) ◽  
pp. 109-118
Author(s):  
E. L. Triplett ◽  
R. Herzog ◽  
L. P. Russell

A population of polysomes isolated from frogskinis capable of supporting protein synthesis in a cell-free system containing an energy generating system, ‘soluble components’, and amino acids. These polysomes catalyse the oxidation of DOPA after gentle trypsinization, and they also have antigenic determinants attributable to tyrosine oxidase. Skin polysomes sedimented in 10–30 % sucrose gradients contain tyrosine oxidase peaks of enzymic activity at the bottom and top of the tube and in the 250 S regions. A peak of tyrosine oxidase antigenic acitvity is found in the 250–350S region of the gradient. Polysomes resolved on the gradient retain the ability to support protein synthesis in a cellfree system. All 250–350S particles capable of supporting the incorporation of [14C]amino acid into tyrosine oxidase are precipitable with tyrosine oxidase antibodies. It is probable that 250–350S tyrosine oxidase antibody precipitates contain only polysomes for this protein.


Blood ◽  
1987 ◽  
Vol 69 (1) ◽  
pp. 219-223 ◽  
Author(s):  
M Poncz ◽  
S Surrey ◽  
P LaRocco ◽  
MJ Weiss ◽  
EF Rappaport ◽  
...  

Abstract We report the isolation of a platelet factor 4 (PF4) cDNA clone from a lambda gt11 expression cDNA library which was derived from a human erythroleukemic (HEL) cell line. The sequence of the DNA insert includes the 3′-untranslated region, the entire amino acid coding region for the mature PF4 protein, and a 5′ region containing coding information for an additional 18 amino acids. In addition, supplemental genomic DNA sequencing shows that the full-length leader sequence is 30 amino acids long plus an initial methionine and codes for a hydrophobic signal-like sequence which is probably involved in transmembrane transport. A single species mRNA of approximately 800 nucleotides was detected on blots of HEL cell poly(A) + RNA using a labeled PF4 cDNA probe. The human PF4 leader sequence shares some DNA, but no amino acid, homology with the 15 amino acids at the N-terminus of mature bovine PF4, suggesting rapid divergence in this region of PF4 between these two species. Sequence comparison of the coding regions of mature PF4 and gamma IP-10, a protein induced in a variety of cells following treatment with gamma-interferon, shows a corrected divergence of 76%. The divergence of a common ancestor protein into PF4 and gamma IP-10 may have accompanied the development of sophisticated immune and coagulation systems in vertebrates. The availability of cDNA and genomic DNA information for these genes in other species will be useful in studying the evolution of the coagulation and immune systems.


1986 ◽  
Vol 235 (3) ◽  
pp. 895-898 ◽  
Author(s):  
M S López de Haro ◽  
A Nieto

An almost full-length cDNA coding for pre-uteroglobin from hare lung was cloned and sequenced. The derived amino acid sequence indicated that hare pre-uteroglobin contained 91 amino acids, including a signal peptide of 21 residues. Comparison of the nucleotide sequence of hare pre-uteroglobin cDNA with that previously reported for the rabbit gene indicated five silent point substitutions and six others leading to amino acid changes in the coding region. The untranslated regions of both pre-uteroglobin mRNAs were very similar. The amino acid changes observed are discussed in relation to the different progesterone-binding abilities of both homologous proteins.


1997 ◽  
Vol 87 (3) ◽  
pp. 295-301 ◽  
Author(s):  
Jianping Chen ◽  
Lesley Torrance ◽  
Graham H. Cowan ◽  
Stuart A. MacFarlane ◽  
Gerald Stubbs ◽  
...  

Four monoclonal antibodies (MAbs) were prepared against an isolate of soilborne wheat mosaic furovirus from Oklahoma (SBWMV Okl-7). Three MAbs had different reactivities in tests on SBWMV isolates from Nebraska (Lab1), France, and Japan. One MAb (SCR 133) also reacted with oat golden stripe furovirus. None of the MAbs cross-reacted with other rod-shaped viruses including beet necrotic yellow vein furovirus, potato mop-top furovirus, and tobacco rattle tobravirus. Sequence analysis of nucleotides between 334 and 1,000 of RNA 2, the region that encodes the coat protein (CP) and the first 44 amino acids of a readthrough protein, of the four SBWMV isolates revealed up to 27 base changes from the published sequence of a Nebraska field isolate of SBWMV. Most changes were translationally silent, but some caused differences of one to three amino acids in residues located near either the N- or C-terminus of the CPs of the different isolates. Two further single amino acid changes were found at the beginning of the readthrough domain of the CP-readthrough protein. Some of these amino acid changes could be discriminated by MAbs SCR 132, SCR 133, and SCR 134. Peptide scanning (Pepscan) analysis indicated that the epitope recognized by SCR 134 is located near the N-terminus of the CP. SCR 132 was deduced to react with a discontinuous CP epitope near the C-terminus, and SCR 133 reacted with a surface-located continuous epitope also near the C-terminus. Predictions of CP structure from computer-assisted three-dimensional model building, by comparison with the X-ray fiber diffraction structure of tobacco mosaic virus, suggested that the three CP amino acids found to differ between isolates of SBWMV were located near the viral surface and were in regions predicted to be antigenic.


2005 ◽  
Vol 71 (9) ◽  
pp. 5501-5510 ◽  
Author(s):  
Sandra W. A. Hinz ◽  
Marieke I. Pastink ◽  
Lambertus A. M. van den Broek ◽  
Jean-Paul Vincken ◽  
Alphons G. J. Voragen

ABSTRACT A putative endogalactanase gene classified into glycoside hydrolase family 53 was revealed from the genome sequence of Bifidobacterium longum strain NCC2705 (Schell et al., Proc. Natl. Acad. Sci. USA 99:14422-14427, 2002). Since only a few endo-acting enzymes from bifidobacteria have been described, we have cloned this gene and characterized the enzyme in detail. The deduced amino acid sequence suggested that this enzyme was located extracellularly and anchored to the cell membrane. galA was cloned without the transmembrane domain into the pBluescript SK(−) vector and expressed in Escherichia coli. The enzyme was purified from the cell extract by anion-exchange and size exclusion chromatography. The purified enzyme had a native molecular mass of 329 kDa, and the subunits had a molecular mass of 94 kDa, which indicated that the enzyme occurred as a tetramer. The optimal pH of endogalactanase activity was 5.0, and the optimal temperature was 37°C, using azurine-cross-linked galactan (AZCL-galactan) as a substrate. The Km and V max for AZCL-galactan were 1.62 mM and 99 U/mg, respectively. The enzyme was able to liberate galactotrisaccharides from (β1→4)galactans and (β1→4)galactooligosaccharides, probably by a processive mechanism, moving toward the reducing end of the galactan chain after an initial midchain cleavage. GalA's mode of action was found to be different from that of an endogalactanase from Aspergillus aculeatus. The enzyme seemed to be able to cleave (β1→3) linkages. Arabinosyl side chains in, for example, potato galactan hindered GalA.


2002 ◽  
Vol 68 (6) ◽  
pp. 2731-2736 ◽  
Author(s):  
Hirokazu Nankai ◽  
Wataru Hashimoto ◽  
Kousaku Murata

ABSTRACT When cells of Bacillus sp. strain GL1 were grown in a medium containing xanthan as a carbon source, α-mannosidase exhibiting activity toward p-nitrophenyl-α-d-mannopyranoside (pNP-α-d-Man) was produced intracellularly. The 350-kDa α-mannosidase purified from a cell extract of the bacterium was a trimer comprising three identical subunits, each with a molecular mass of 110 kDa. The enzyme hydrolyzed pNP-α-d-Man (Km = 0.49 mM) and d-mannosyl-(α-1,3)-d-glucose most efficiently at pH 7.5 to 9.0, indicating that the enzyme catalyzes the last step of the xanthan depolymerization pathway of Bacillus sp. strain GL1. The gene for α-mannosidase cloned most by using N-terminal amino acid sequence information contained an open reading frame (3,144 bp) capable of coding for a polypeptide with a molecular weight of 119,239. The deduced amino acid sequence showed homology with the amino acid sequences of α-mannosidases belonging to glycoside hydrolase family 38.


1979 ◽  
Vol 184 (2) ◽  
pp. 421-426 ◽  
Author(s):  
J O'Sullivan ◽  
R C Bleaney ◽  
J A Huddleston ◽  
E P Abraham

1. delta-(L-alpha-Amino[4,5-3H]adipyl)-L-cysteinyl-D-[4,4-3H]valine has been synthesized from its constituent amino acids, the L-alpha-amino[4,5-3H]adipic acid being obtained by reduction with 3H2 of methyl 5-acetamido-5,5-diethoxycarbonylpent-2-enoate and subsequent decarboxylation and hydrolysis. 2. In a cell-free system prepared by lysis of protoplasts of Cephalosporium acremonium 3H was incorporated from the doubly labelled tripeptide into a compound that behaved like penicillin N or isopenicillin N. The relative specific radioactivities of the alpha-aminoadipyl and penicillamine moieties of the penicillin were the same (within experimental error) as those of the alpha-aminoadipic acid and valine residues respectively of the tripeptide. 3. The behaviour of the labelled alpha-aminoadipic acid from the penicillin to the L-amino acid oxidase of Crotalus adamanteus venom showed that it was mainly L-alpha-aminoadipic acid. 4. The results are consistent with the hypothesis that the carbon skeleton of the LLD-tripeptide is incorporated intact into the penicillin molecule and that the first product is isopenicillin N.


1968 ◽  
Vol 109 (1) ◽  
pp. 19-24 ◽  
Author(s):  
Louise Oliver ◽  
Anne Stockell Hartree

The cystine-containing peptides of horse growth hormone were isolated and their amino acid sequences determined. Four unique half-cystine residues occur in two peptides, one containing 11 and the other, at the C-terminus of the protein, 15 amino acids. These sequences are compared with published data on growth hormones from other species.


Sign in / Sign up

Export Citation Format

Share Document