scholarly journals Human liver glutathione S-transferase ψ. Chemical characterization and secondary-structure comparison with other mammalian glutathione S-transferases

1987 ◽  
Vol 243 (1) ◽  
pp. 61-67 ◽  
Author(s):  
S V Singh ◽  
A Kurosky ◽  
Y C Awasthi
Keyword(s):  
Amino Acid ◽  
Secondary Structure ◽  
Human Liver ◽  
Chemical Characterization ◽  
Compositional Analysis ◽  
Amino Acid Sequences ◽  
Terminal Region ◽  
Glutathione S Transferase ◽  
Structure Comparison ◽  
Liver Glutathione

The isolation and chemical characterization of the anionic human liver glutathione S-transferase (GST) psi (pI 5.5) are described and compared with other GST isoenzymes reported for rat and human. Amino acid compositional analysis, substrate specificity and isoelectric focusing indicated that GST psi is a unique isoenzyme form of GST. Strikingly, however, amino acid sequence analysis of the N-terminal region indicated that GST psi was identical with GST mu in the first 23 amino acid residues reported. It is likely that these two enzyme forms are at least partially structurally related. In order to investigate further the genetic relationship of GST psi to other reported GST isoenzymes, secondary-structure analysis was performed. Despite substantial differences in the N-terminal-region amino acid sequences of some of the GST isoenzymes, the secondary structure of all the isoenzymes is highly conserved at their N-termini. The general uniformity of the secondary structure of this enzyme class at their N-termini strongly indicated that the observed diversity of these isoenzymes probably occurred as a result of a mechanism of gene duplication followed by divergence rather than a mechanism of convergent evolution.

scholarly journals Characterization of the Gallate Dioxygenase Gene: Three Distinct Ring Cleavage Dioxygenases Are Involved in Syringate Degradation by Sphingomonas paucimobilis SYK-6

2005 ◽  
Vol 187 (15) ◽  
pp. 5067-5074 ◽  
Author(s):  
Daisuke Kasai ◽  
Eiji Masai ◽  
Keisuke Miyauchi ◽  
Yoshihiro Katayama ◽  
Masao Fukuda
Keyword(s):  
Amino Acid ◽  
Amino Acid Sequences ◽  
Terminal Region ◽  
Ring Cleavage ◽  
Sphingomonas Paucimobilis ◽  
Acid Protein ◽  
Demethylation Pathway ◽  
Dioxygenase Gene ◽  
Amino Acid Protein

ABSTRACT Sphingomonas paucimobilis SYK-6 converts vanillate and syringate to protocatechuate (PCA) and 3-O-methylgallate (3MGA) in reactions with the tetrahydrofolate-dependent O-demethylases LigM and DesA, respectively. PCA is further degraded via the PCA 4,5-cleavage pathway, whereas 3MGA is metabolized via three distinct pathways in which PCA 4,5-dioxygenase (LigAB), 3MGA 3,4-dioxygenase (DesZ), and 3MGA O-demethylase (LigM) are involved. In the 3MGA O-demethylation pathway, LigM converts 3MGA to gallate, and the resulting gallate appears to be degraded by a dioxygenase other than LigAB or DesZ. Here, we isolated the gallate dioxygenase gene, desB, which encodes a 418-amino-acid protein with a molecular mass of 46,843 Da. The amino acid sequences of the N-terminal region (residues 1 to 285) and the C-terminal region (residues 286 to 418) of DesB exhibited ca. 40% and 27% identity with the sequences of the PCA 4,5-dioxygenase β and α subunits, respectively. DesB produced in Escherichia coli was purified and was estimated to be a homodimer (86 kDa). DesB specifically attacked gallate to generate 4-oxalomesaconate as the reaction product. The Km for gallate and the V max were determined to be 66.9 ± 9.3 μM and 42.7 ± 2.4 U/mg, respectively. On the basis of the analysis of various SYK-6 mutants lacking the genes involved in syringate degradation, we concluded that (i) all of the three-ring cleavage dioxygenases are involved in syringate catabolism, (ii) the pathway involving LigM and DesB plays an especially important role in the growth of SYK-6 on syringate, and (iii) DesB and LigAB are involved in gallate degradation.

scholarly journals Molecular cloning of two human liver 3 α-hydroxysteroid/dihydrodiol dehydrogenase isoenzymes that are identical with chlordecone reductase and bile-acid binder

1994 ◽  
Vol 299 (2) ◽  
pp. 545-552 ◽  
Author(s):  
Y Deyashiki ◽  
A Ogasawara ◽  
T Nakayama ◽  
M Nakanishi ◽  
Y Miyabe ◽  
...  
Keyword(s):  
Bile Acid ◽  
Amino Acid ◽  
Human Liver ◽  
Polyclonal Antibodies ◽  
Amino Acid Sequences ◽  
Cdna Clones ◽  
Amino Acid Residues ◽  
Human Bile ◽  
Coding Regions ◽  
Computer Based

Human liver contains two dihydrodiol dehydrogenases, DD2 and DD4, associated with 3 alpha-hydroxysteroid dehydrogenase activity. We have raised polyclonal antibodies that cross-reacted with the two enzymes and isolated two 1.2 kb cDNA clones (C9 and C11) for the two enzymes from a human liver cDNA library using the antibodies. The clones of C9 and C11 contained coding sequences corresponding to 306 and 321 amino acid residues respectively, but lacked 5′-coding regions around the initiation codon. Sequence analyses of several peptides obtained by enzymic and chemical cleavages of the two purified enzymes verified that the C9 and C11 clones encoded DD2 and DD4 respectively, and further indicated that the sequence of DD2 had at least additional 16 residues upward from the N-terminal sequence deduced from the cDNA. There was 82% amino acid sequence identity between the two enzymes, indicating that the enzymes are genetic isoenzymes. A computer-based comparison of the cDNAs of the isoenzymes with the DNA sequence database revealed that the nucleotide and amino acid sequences of DD2 and DD4 are virtually identical with those of human bile-acid binder and human chlordecone reductase cDNAs respectively.

scholarly journals Molecular cloning, sequencing and expression of the cDNA of the mitochondrial form of phosphoenolpyruvate carboxykinase from human liver

1996 ◽  
Vol 315 (3) ◽  
pp. 807-814 ◽  
Author(s):  
Said MODARESSI ◽  
Bruno CHRIST ◽  
Jutta BRATKE ◽  
Stefan ZAHN ◽  
Tilman HEISE ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Human Liver ◽  
Phosphoenolpyruvate Carboxykinase ◽  
Amino Acid Level ◽  
Cdna Probe ◽  
Rat Hepatocytes ◽  
Eukaryotic Expression ◽  
Amino Acid Sequences ◽  
Sequence Identity

In human liver, phosphoenolpyruvate carboxykinase (PCK; EC 4.1.1.32) is about equally distributed between cytosol and mitochondria in contrast with rat liver in which it is essentially a cytosolic enzyme. Recently, the isolation of the gene and cDNA of the human cytosolic enzyme has been reported [Ting, Burgess, Chamberlain, Keith, Falls and Meisler (1993) Genomics 16, 698–706; Stoffel, Xiang, Espinosa, Cox, Le Beau and Bell (1993) Hum. Mol. Genet. 2, 1–4]. It was the goal of this investigation to isolate the cDNA of the human mitochondrial form of hepatic PCK. A human liver cDNA library was screened with a rat cytosolic PCK cDNA probe comprising sequences from exons 2 to 9. A cDNA clone was isolated which had overall a 68% DNA sequence and a 70% deduced amino acid sequence identity with the human cytosolic PCK cDNA. Without the flanking 270 bases (=90 amino acids) each at the 5´ and 3´ end, the sequence identity was 73% on the DNA and 78% on the amino acid level. The isolated cDNA had an open reading frame of 1920 bp; it was 54 bp (equivalent to 18 amino acids) longer than that of human or rat cytosolic PCK cDNA. The isolated cDNA was cloned into the eukaryotic expression vector pcDNAI and transfected into human embryonal kidney cells HEK293; PCK activity was increased by 3-fold in the mitochondria, which normally contain 70% of total PCK activity, but not in the cytosol. The isolated cDNA was also transfected into cultured rat hepatocytes; again, PCK activity was enhanced by about 40-fold in the mitochondria, which normally possess only 10% of total PCK activity, but not in the cytosol. In the rat hepatocytes only the endogenous cytosolic PCK and not the transfected mitochondrial PCK was induced 3-fold with glucagon. Comparison of the amino acid sequences deduced from the isolated cDNA with human and rat cytosolic PCK showed that the additional 18 amino acids were located at the N-terminus of the protein and probably constitute a mitochondrial targeting signal. Northern-blot analyses revealed the human mitochondrial PCK mRNA to be 2.25 kb long, about 0.6 kb shorter than the mRNA of the cytosolic PCK. Primer extension experiments showed that the 5´-untranslated region of mitochondrial PCK mRNA was 134 nucleotides in length.

Amino acid sequence of penicillopepsin. I. Isolation and characterization of the chymotryptic peptides

1976 ◽  
Vol 54 (10) ◽  
pp. 872-884 ◽  
Author(s):  
Alexander Kurosky ◽  
Theo Hofmann
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Amino Acid Sequence ◽  
Amino Acid Sequences ◽  
Acid Protease ◽  
Terminal Region ◽  
Isolation And Characterization

The amino acid sequences of 48 peptides obtained from a chymotryptic digest of the mould acid protease, penicillopepsin (EC 3.4.23.7), have been determined. These peptides established the sequences of 26 unique fragments of up to 28 residues in length. The 28-residue fragment was identified as the N-terminal region. The C-terminal region is represented by a 13-residue fragment. The amino acids contained in these fragments account for some 85% of the residues of the enzyme.

scholarly journals NewSacl RFLP for human liver glutathione-S-transferase

1991 ◽  
Vol 19 (1) ◽  
pp. 199-199
Author(s):  
D.C.Van Dyke ◽  
J. Roby ◽  
C.-P.D. Tu
Keyword(s):  
Human Liver ◽  
Glutathione S Transferase ◽  
Liver Glutathione

scholarly journals Plant and Bacterial Metaxin-like Proteins: Novel Proteins Related to Vertebrate Metaxins Involved in Uptake of Nascent Proteins into Mitochondria

2020 ◽  
Author(s):  
Kenneth W. Adolph
Keyword(s):  
Amino Acid ◽  
Protein Import ◽  
Protein Domains ◽  
Amino Acid Sequences ◽  
Similar Degree ◽  
Glutathione S Transferase ◽  
Phylogenetic Groups ◽  
Bacterial Phyla ◽  
Novel Proteins ◽  
Plant Groups

ABSTRACTThe metaxins were originally identified as vertebrate proteins of the outer mitochondrial membrane involved in protein import into mitochondria. Metaxin proteins have also been found in diverse invertebrate phyla. The present study is concerned with examining whether metaxin-like proteins occur in plants and bacteria. Metaxin-like proteins were revealed by their homology with human metaxins and the possession of characteristic GST_Metaxin protein domains. The results demonstrate that metaxin-like proteins exist in plants that include a wide variety of angiosperms, both eudicots and monocots, and other plant groups. Metaxin-like proteins can also be detected in bacteria, particularly in the Proteobacteria phylum, but also in different bacterial phyla. Phylogenetic analysis indicates that plant metaxin-like proteins, bacterial metaxin-like proteins, and vertebrate metaxins form distinct phylogenetic groups, but are related. Metaxin-like proteins, however, are only distantly related to GSTs (glutathione S-transferase proteins). A similar degree of homology is found in aligning the amino acid sequences of plant and bacterial metaxin-like proteins with human metaxins 1, 2, and 3 and other vertebrate metaxins. The amino acid identities range from about 22%-28% for each alignment. The presence of two conserved protein domains, GST_N_Metaxin and GST_C_Metaxin, in both plant and bacterial metaxin-like proteins provides evidence that these proteins are related to the vertebrate and invertebrate metaxins. The metaxin-like proteins have predicted secondary structures that are dominated by alpha-helical segments, like the vertebrate and invertebrate metaxins.

scholarly journals The occurrence in amino acid sequences of extensive informational symmetries based on possible codon-codon complementarity in the encoding polynucleotides

1976 ◽  
Vol 153 (3) ◽  
pp. 681-690 ◽  
Author(s):  
G M Polya ◽  
D R Phillips
Keyword(s):  
Amino Acid ◽  
Secondary Structure ◽  
Amino Acid Sequence ◽  
Basic Protein ◽  
Protein A ◽  
Protein Sequences ◽  
Amino Acid Sequences ◽  
Rat Skin ◽  
Skin Collagen ◽  
Low Probability

1. A procedure is described for the detection and assessment of informational complementarity in an amino acid sequence; it is based on possible autocomplementarity in the mRNA, and involves codon-to-codon matching. 2. This procedure was applied to myelin basic protein, a variety of protamines, histone IV, silk fibroin, rat skin collagen α1 chain and a sheep keratin. A multiplicity of extensive low-probability informational symmetries, based on codon-to-codon matching, were detected. 3. These low-probability orderings, which are independent of the actual mRNA codons, are rationalized in terms of the evolutionary ordering of the amino acid sequences concerned, in such a way that constraints on the secondary structure of the coding polynucleotides were satisfied. This possible interpretation is supported by a number of significant common properties of the protein sequences analysed.

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