scholarly journals Falcatimonas natans gen. nov., sp. nov., a strictly anaerobic, amino-acid-decomposing bacterium isolated from a methanogenic reactor of cattle waste

2016 ◽  
Vol 66 (11) ◽  
pp. 4639-4644 ◽  
Author(s):  
Misa Watanabe ◽  
Nobuo Kaku ◽  
Katsuji Ueki ◽  
Atsuko Ueki
Keyword(s):  
Amino Acid ◽  
Strictly Anaerobic

scholarly journals Sulphoacetaldehyde sulpho-lyase (EC 4.4.1.12) from Desulfonispora thiosulfatigenes: purification, properties and primary sequence

2001 ◽  
Vol 357 (2) ◽  
pp. 581-586 ◽  
Author(s):  
Karin DENGER ◽  
Jürgen RUFF ◽  
Ulrike REIN ◽  
Alasdair M. COOK
Keyword(s):  
Amino Acid ◽  
Molecular Mass ◽  
Pcr Primers ◽  
Amino Acid Sequences ◽  
Thiamine Pyrophosphate ◽  
Strictly Anaerobic ◽  
Laser Desorption Ionization ◽  
Native Form ◽  
Ionization Time ◽  
Sds Page

The strictly anaerobic bacterium Desulfonispora thiosulfatigenes ferments taurine via sulphoacetaldehyde, which is hydrolysed to acetate and sulphite by sulphoacetaldehyde sulpho-lyase (EC 4.4.1.12). The lyase was expressed at high levels and a two-step, 4.5-fold purification yielded an apparently homogeneous soluble protein, which was presumably a homodimer in its native form; the molecular mass of the subunit was about 61kDa (by SDS/PAGE). The mass was determined to be 63.8kDa by matrix-assisted laser-desorption ionization–time-of-flight (MALDI–TOF) MS. The purified enzyme converted 1mol of sulphoacetaldehyde to 1mol each of sulphite and acetate, but no requirement for thiamine pyrophosphate (TPP) was detected. The N-terminal and two internal amino acid sequences were determined, which allowed us to generate PCR primers. The gene was amplified and sequenced. The DNA sequence had no significant homologue in the databases searched, whereas the derived amino acid sequence indicated an oxo-acid lyase, revealed a TPP-binding site and gave a derived molecular mass of 63.8kDa.

scholarly journals Characterization of (R)-2-Hydroxyisocaproate Dehydrogenase and a Family III Coenzyme A Transferase Involved in Reduction of l-Leucine to Isocaproate by Clostridium difficile

2006 ◽  
Vol 72 (9) ◽  
pp. 6062-6069 ◽  
Author(s):  
Jihoe Kim ◽  
Daniel Darley ◽  
Thorsten Selmer ◽  
Wolfgang Buckel
Keyword(s):  
Amino Acid ◽  
Clostridium Difficile ◽  
Coenzyme A ◽  
Amino Acid Sequences ◽  
Site Directed Mutagenesis ◽  
Transferase Activity ◽  
Strictly Anaerobic ◽  
Radical Intermediates ◽  
Coa Transferase ◽  
Genes Encoding

ABSTRACT The strictly anaerobic pathogenic bacterium Clostridium difficile occurs in the human gut and is able to thrive from fermentation of leucine. Thereby the amino acid is both oxidized to isovalerate plus CO2 and reduced to isocaproate. In the reductive branch of this pathway, the dehydration of (R)-2-hydroxyisocaproyl-coenzyme A (CoA) to (E)-2-isocaprenoyl-CoA is probably catalyzed via radical intermediates. The dehydratase requires activation by an ATP-dependent one-electron transfer (J. Kim, D. Darley, and W. Buckel, FEBS J. 272:550-561, 2005). Prior to the dehydration, a dehydrogenase and a CoA transferase are supposed to be involved in the formation of (R)-2-hydroxyisocaproyl-CoA. Deduced amino acid sequences of ldhA and hadA from the genome of C. difficile showed high identities to d-lactate dehydrogenase and family III CoA transferase, respectively. Both putative genes encoding the dehydrogenase and CoA transferase were cloned and overexpressed in Escherichia coli; the recombinant Strep tag II fusion proteins were purified to homogeneity and characterized. The substrate specificity of the monomeric LdhA (36.5 kDa) indicated that 2-oxoisocaproate (Km = 68 μM, k cat = 31 s−1) and NADH were the native substrates. For the reverse reaction, the enzyme accepted (R)- but not (S)-2-hydroxyisocaproate and therefore was named (R)-2-hydroxyisocaproate dehydrogenase. HadA showed CoA transferase activity with (R)-2-hydroxyisocaproyl-CoA as a donor and isocaproate or (E)-2-isocaprenoate as an acceptor. By site-directed mutagenesis, the conserved D171 was identified as an essential catalytic residue probably involved in the formation of a mixed anhydride with the acyl group of the thioester substrate. However, neither hydroxylamine nor sodium borohydride, both of which are inactivators of the CoA transferase, modified this residue. The dehydrogenase and the CoA transferase fit well into the proposed pathway of leucine reduction to isocaproate.

The staining pattern of the tropomyosin sequence is displayed in a new paracrystal

1986 ◽  
Vol 44 ◽  
pp. 150-151
Author(s):  
M.K. Lamvik ◽  
L.L. Klatt
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequence ◽  
Staining Pattern ◽  
Banding Patterns ◽  
Mass Thickness ◽  
New Form

Tropomyosin paracrystals have been used extensively as test specimens and magnification standards due to their clear periodic banding patterns. The paracrystal type discovered by Ohtsuki1 has been of particular interest as a test of unstained specimens because of alternating bands that differ by 50% in mass thickness. While producing specimens of this type, we came across a new paracrystal form. Since this new form displays aligned tropomyosin molecules without the overlaps that are characteristic of the Ohtsuki-type paracrystal, it presents a staining pattern that corresponds to the amino acid sequence of the molecule.

Electron probe x-ray microanalysis and electron microscopy of amino acid absorption and transport by the small intestine: inhibition by chemical poisons and correlation to the elemental composition of the epithelial cells

1986 ◽  
Vol 44 ◽  
pp. 134-135
Author(s):  
A. J. Tousimis
Keyword(s):  
Small Intestine ◽  
Amino Acid ◽  
Epithelial Cells ◽  
Elemental Composition ◽  
Isotope Labeling ◽  
Structural Components ◽  
X Ray ◽  
Human Small Intestine ◽  
Transport Studies

The elemental composition of amino acids is similar to that of the major structural components of the epithelial cells of the small intestine and other tissues. Therefore, their subcellular localization and concentration measurements are not possible by x-ray microanalysis. Radioactive isotope labeling: I131-tyrosine, Se75-methionine and S35-methionine have been successfully employed in numerous absorption and transport studies. The latter two have been utilized both in vitro and vivo, with similar results in the hamster and human small intestine. Non-radioactive Selenomethionine, since its absorption/transport behavior is assumed to be the same as that of Se75- methionine and S75-methionine could serve as a compound tracer for this amino acid.

Immunoelectron microscope detection of C-type natriuretic peptide in normal human atrial tissue

1993 ◽  
Vol 51 ◽  
pp. 388-389
Author(s):  
Chi-Ming Wei ◽  
Margaret Hukee ◽  
Christopher G.A. McGregor ◽  
John C. Burnett
Keyword(s):  
Amino Acid ◽  
Natriuretic Peptide ◽  
Vascular Tone ◽  
Cardiac Tissue ◽  
Ring Structure ◽  
Terminal Amino Acid ◽  
Amino Acid Peptide ◽  
Normal Human ◽  
Terminal Amino ◽  
The Brain

C-type natriuretic peptide (CNP) is a newly identified peptide that is structurally related to atrial (ANP) and brain natriuretic peptide (BNP). CNP exists as a 22-amino acid peptide and like ANP and BNP has a 17-amino acid ring formed by a disulfide bond. Unlike these two previously identified cardiac peptides, CNP lacks the COOH-terminal amino acid extension from the ring structure. ANP, BNP and CNP decrease cardiac preload, but unlike ANP and BNP, CNP is not natriuretic. While ANP and BNP have been localized to the heart, recent investigations have failed to detect CNP mRNA in the myocardium although small concentrations of CNP are detectable in the porcine myocardium. While originally localized to the brain, recent investigations have localized CNP to endothelial cells consistent with a paracrine role for CNP in the control of vascular tone. While CNP has been detected in cardiac tissue by radioimmunoassay, no studies have demonstrated CNP localization in normal human heart by immunoelectron microscopy.

Amino Acid Metabolism

1979 ◽  
Vol 7 (1) ◽  
pp. 261-262
Author(s):  
E. V. ROWSELL
Keyword(s):  
Amino Acid ◽  
Amino Acid Metabolism ◽  
Acid Metabolism

Increased expression of an amino acid transporter LAT1 in healing of acetic acid-induced chronic gastric ulcer in rats

2001 ◽  
Vol 120 (5) ◽  
pp. A153-A153
Author(s):  
S MIYAMOTO ◽  
K KATO ◽  
Y ISHII ◽  
S ASAI ◽  
T NAGAISHI ◽  
...  
Keyword(s):  
Acetic Acid ◽  
Gastric Ulcer ◽  
Amino Acid ◽  
Amino Acid Transporter ◽  
Chronic Gastric Ulcer ◽  
Acid Transporter
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