scholarly journals Human thimet oligopeptidase

1993 ◽  
Vol 294 (2) ◽  
pp. 451-457 ◽  
Author(s):  
P M Dando ◽  
M A Brown ◽  
A J Barrett
Keyword(s):  
Amino Acid ◽  
Substrate Specificity ◽  
The Other ◽  
Amino Acid Residues ◽  
Reversible Inhibitors ◽  
Hydrophobic Residues ◽  
The Past ◽  
Human Enzyme ◽  
C Terminus ◽  
Thimet Oligopeptidase

We have purified human thimet oligopeptidase to homogeneity from erythrocytes, and compared it with the enzyme from rat testis and chicken liver. An antiserum raised against rat thimet oligopeptidase also recognized the human and chicken enzymes, suggesting that the structure of the enzyme has been strongly conserved in evolution. Consistent with this, the properties of the human enzyme were very similar to those for the other species. Thus human thimet oligopeptidase also is a thiol-dependent metallo-oligopeptidase with M(r) about 75,000. Specificity for cleavage of a number of peptides was indistinguishable from that of the rat enzyme, but Ki values for the four potent reversible inhibitors tested were lower. In discussing the results, we consider the determinants of the complex substrate specificity of thimet oligopeptidase. We question whether substrates containing more than 17 amino acid residues are cleaved, as has been suggested. We also point out that the favourable location of a proline residue and a free C-terminus in the substrate may be as important as the hydrophobic residues in the P2, P1 and P3′ positions that have been emphasized in the past.

scholarly journals Chimeric Clostridial Cytotoxins: Identification of the N-Terminal Region Involved in Protein Substrate Recognition

1998 ◽  
Vol 66 (3) ◽  
pp. 1076-1081 ◽  
Author(s):  
Fred Hofmann ◽  
Christian Busch ◽  
Klaus Aktories
Keyword(s):  
Amino Acid ◽  
Substrate Specificity ◽  
Small Gtpases ◽  
Lethal Toxin ◽  
Amino Acid Residues ◽  
Toxin B ◽  
Protein Substrate ◽  
C Terminus ◽  
The Family ◽  
Active Fragment

ABSTRACT Clostridium sordellii lethal toxin is a member of the family of large clostridial cytotoxins that glucosylate small GTPases. In contrast to Clostridium difficile toxins A and B, which exclusively modify Rho subfamily proteins, C. sordelliilethal toxin also glucosylates Ras subfamily proteins. By deletion analysis and construction of chimeric fusion proteins of C. sordellii lethal toxin and C. difficile toxin B, we localized the enzyme activity of the lethal toxin to the N terminus of the holotoxin and identified the region involved in protein substrate specificity. The toxin fragment of the N-terminal 546 amino acid residues of C. sordellii lethal toxin glucosylated Rho and Ras subfamily proteins, as the holotoxin did. Deletion of a further 30 amino acid residues from the C terminus of this active fragment drastically reduced glucotransferase activity and blocked glucohydrolase activity. Exchange of amino acid residues 364 through 516 of lethal toxin for those in the active toxin B fragment (1 to 546) allowed glucosylation of Ras subfamily proteins. In contrast, the chimera with amino acids 1 to 364 from toxin B, 365 to 468 from lethal toxin, and 469 to 546 from toxin B exhibited markedly reduced modification of Ras subfamily proteins, whereas modification of Rac and Cdc42 was hardly changed. The data indicate that the region of amino acid residues 364 through 516 primarily defines the substrate specificity of C. sordellii lethal toxin.

scholarly journals Structural features that make oligopeptides susceptible substrates for hydrolysis by recombinant thimet oligopeptidase

1997 ◽  
Vol 324 (2) ◽  
pp. 517-522 ◽  
Author(s):  
Antonio. C. M CAMARGO ◽  
Marcelo. D GOMES ◽  
Antonia. P REICHL ◽  
Emer. S FERRO ◽  
Saul JACCHIERI ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Cleavage Site ◽  
Catalytic Efficiency ◽  
Structural Features ◽  
Amino Acid Residues ◽  
Systematic Analysis ◽  
Peptide Bonds ◽  
C Terminus ◽  
Thimet Oligopeptidase

A systematic analysis of the peptide sequences and lengths of several homologues of bioactive peptides and of a number of quenched-fluorescence (qf) opioid- and bradykinin-related peptides was performed to determine the main features leading the oligopeptides to hydrolysis by the recombinant rat testis thimet oligopeptidase (EC 3.4.24.15). The results indicate that a minimum substrate length of six amino acids is required and that among the oligopeptides six to thirteen amino acid residues long, their susceptibility as substrates is highly variable. Thimet oligopeptidase was able to hydrolyse, with similar catalytic efficiency, peptide bonds having hydrophobic or hydrophilic amino acids as well as proline in the P1 position of peptides, ranging from a minimum of six to a maximum of approximately thirteen amino acid residues. An intriguing observation was the shift of the cleavage site, at a Leu-Arg bond in qf dynorphin-(2–8) [qf-Dyn2–8; Abz-GGFLRRV-EDDnp, where Abz stands for o-aminobenzoyl and EDDnp for N-(2,4-dinitrophenyl) ethylenediamine], to Arg-Arg in qf-Dyn2–8Q, in which Gln was substituted for Val at its C-terminus. Similarly, a cleavage site displacement was also observed with the hydrolysis of the internally quenched-fluorescence bradykinin analogues containing Gln at the C-terminal position, namely Abz-RPPGFSPFR-EDDnp and Abz-GFSPFR-EDDnp are cleaved at the Phe-Ser bond, but Abz-RPPGFSPFRQ-EDDnp and Abz-GFSPFRQ-EDDnp are cleaved at the Pro-Phe bond.

Oxytocin analogues with non-coded amino acid residues in position 8: [8-Neopentylglycine]oxytocin and [8-cycloleucine]oxytocin

1987 ◽  
Vol 52 (9) ◽  
pp. 2317-2325 ◽  
Author(s):  
Jan Hlaváček ◽  
Jan Pospíšek ◽  
Jiřina Slaninová ◽  
Walter Y. Chan ◽  
Victor J. Hruby
Keyword(s):  
Amino Acid ◽  
Solid Phase Synthesis ◽  
Solid Phase ◽  
The Other ◽  
Amino Acid Residues ◽  
Phase Synthesis ◽  
Other Hand ◽  
Fragment Condensation

[8-Neopentylglycine]oxytocin (II) and [8-cycloleucine]oxytocin (III) were prepared by a combination of solid-phase synthesis and fragment condensation. Both analogues exhibited decreased uterotonic potency in vitro, each being about 15-30% that of oxytocin. Analogue II also displayed similarly decreased uterotonic potency in vivo and galactogogic potency. On the other hand, analogue III exhibited almost the same potency as oxytocin in the uterotonic assay in vivo and in the galactogogic assay.

scholarly journals Primary- and secondary-structural analysis of a unique prokaryotic metallothionein from a Synechococcus sp. cyanobacterium

1988 ◽  
Vol 251 (3) ◽  
pp. 691-699 ◽  
Author(s):  
R W Olafson ◽  
W D McCubbin ◽  
C M Kay
Keyword(s):  
Amino Acid ◽  
Metal Binding ◽  
Helical Structure ◽  
Basic Amino Acid ◽  
Cysteine Residues ◽  
Amino Acid Residues ◽  
C Terminus ◽  
Empirical Relations ◽  
Heavy Metal Binding ◽  
Synechococcus Sp

Biochemical and physiological studies of Synechococcus cyanobacteria have indicated the presence of a low-Mr heavy-metal-binding protein with marked similarity to eukaryotic metallothioneins (MTs). We report here the characterization of a Synechococcus prokaryotic MT isolated by gel-permeation and reverse-phase chromatography. The large number of variants of this molecule found during chromatographic separation could not be attributed to the presence of major isoproteins as assessed by amino acid analysis and amino acid sequencing of isoforms. Two of the latter were shown to have identical primary structures that differed substantially from the well-described eukaryotic MTs. In addition to six long-chain aliphatic residues, two aromatic residues were found adjacent to one another near the centre of the molecule, making this the most hydrophobic MT to be described. Other unusual features included a pair of histidine residues located in repeating Gly-His-Thr-Gly sequences near the C-terminus and a complete lack of association of hydroxylated residues with cysteine residues, as is commonly found in eukaryotes. Similarly, aside from a single lysine residue, no basic amino acid residues were found adjacent to cysteine residues in the sequence. Most importantly, sequence alignment analyses with mammalian, invertebrate and fungal MT sequences showed no statistically significant homology aside from the presence of Cys-Xaa-Cys structures common to all MTs. On the other hand, like other MTs, the prokaryotic molecule appears to be free of alpha-helical structure but has a considerable amount of beta-structure, as predicted by both c.d. measurements and the Chou & Fasman empirical relations. Considered together, these data suggested that some similarity between the metal-thiolate clusters of the prokaryote and eukaryote MTs may exist.

scholarly journals Deletion of the Actin-Associated Tropomyosin Tpm3 Leads to Reduced Cell Complexity in Cultured Hippocampal Neurons—New Insights into the Role of the C-Terminal Region of Tpm3.1

Cells ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 715
Author(s):  
Tamara Tomanić ◽  
Claire Martin ◽  
Holly Stefen ◽  
Esmeralda Parić ◽  
Peter Gunning ◽  
...  
Keyword(s):  
Amino Acid ◽  
Hippocampal Neurons ◽  
Molecular Mechanisms ◽  
Growth Cones ◽  
Amino Acid Residues ◽  
Terminal Amino Acid ◽  
C Terminus ◽  
Primary Mouse ◽  
Terminal Amino

Tropomyosins (Tpms) have been described as master regulators of actin, with Tpm3 products shown to be involved in early developmental processes, and the Tpm3 isoform Tpm3.1 controlling changes in the size of neuronal growth cones and neurite growth. Here, we used primary mouse hippocampal neurons of C57/Bl6 wild type and Bl6Tpm3flox transgenic mice to carry out morphometric analyses in response to the absence of Tpm3 products, as well as to investigate the effect of C-terminal truncation on the ability of Tpm3.1 to modulate neuronal morphogenesis. We found that the knock-out of Tpm3 leads to decreased neurite length and complexity, and that the deletion of two amino acid residues at the C-terminus of Tpm3.1 leads to more detrimental changes in neurite morphology than the deletion of six amino acid residues. We also found that Tpm3.1 that lacks the 6 C-terminal amino acid residues does not associate with stress fibres, does not segregate to the tips of neurites, and does not impact the amount of the filamentous actin pool at the axonal growth cones, as opposed to Tpm3.1, which lacks the two C-terminal amino acid residues. Our study provides further insight into the role of both Tpm3 products and the C-terminus of Tpm3.1, and it forms the basis for future studies that aim to identify the molecular mechanisms underlying Tpm3.1 targeting to different subcellular compartments.

Prediction of amino acid residues participated in substrate recognition by cytochrome P450 subfamilies with broad substrate specificity

2013 ◽  
Vol 26 (2) ◽  
pp. 86-91 ◽  
Author(s):  
Maria S. Zharkova ◽  
Boris N. Sobolev ◽  
Nina Yu. Oparina ◽  
Alexander V. Veselovsky ◽  
Alexander I. Archakov
Keyword(s):  
Cytochrome P450 ◽  
Amino Acid ◽  
Substrate Specificity ◽  
Substrate Recognition ◽  
Amino Acid Residues ◽  
Broad Substrate Specificity

Peroxisome targeting signal of rat liver acyl-coenzyme A oxidase resides at the carboxy terminus

1989 ◽  
Vol 9 (1) ◽  
pp. 83-91
Author(s):  
S Miyazawa ◽  
T Osumi ◽  
T Hashimoto ◽  
K Ohno ◽  
S Miura ◽  
...  
Keyword(s):  
Amino Acid ◽  
Rat Liver ◽  
Coenzyme A ◽  
Terminal Region ◽  
Proteinase K ◽  
Amino Acid Residues ◽  
C Terminus ◽  
Targeting Signal ◽  
Acyl Coenzyme A

To identify the topogenic signal of peroxisomal acyl-coenzyme A oxidase (AOX) of rat liver, we carried out in vitro import experiments with mutant polypeptides of the enzyme. Full-length AOX and polypeptides that were truncated at the N-terminal region were efficiently imported into peroxisomes, as determined by resistance to externally added proteinase K. Polypeptides carrying internal deletions in the C-terminal region exhibited much lower import activities. Polypeptides that were truncated or mutated at the extreme C terminus were totally import negative. When the five amino acid residues at the extreme C terminus were attached to some of the import-negative polypeptides, the import activities were rescued. Moreover, the C-terminal 199 and 70 amino acid residues of AOX directed fusion proteins with two bacterial enzymes to peroxisomes. These results are interpreted to mean that the peroxisome targeting signal of AOX residues at the C terminus and the five or fewer residues at the extreme terminus have an obligatory function in targeting. The C-terminal internal region also has an important role for efficient import, possibly through a conformational effect.

New Antibiotic Uperin Peptides From the Dorsal Glands of the Australian Toadlet Uperoleia mjobergii

1996 ◽  
Vol 49 (12) ◽  
pp. 1325 ◽  
Author(s):  
AM Bradford ◽  
JH Bowie ◽  
MJ Tyler ◽  
JC Wallace
Keyword(s):  
Mass Spectrometry ◽  
Amino Acid ◽  
Related Species ◽  
Antibiotic Activity ◽  
Amino Acid Sequences ◽  
The Other ◽  
Cationic Peptides ◽  
Amino Acid Residues ◽  
Skin Glands ◽  
Edman Sequencing

The dorsal glandular extract of the toadlet Uperoleia mjobergii contains more than 20 peptides. We report the amino acid sequences of the seven major peptides: these were determined by a combination of mass spectrometry and automated Edman sequencing. Three of these peptides have 19 amino acid residues and belong to the uperin 2 group of peptides [e.g. uperin 2.6, Gly Ile Leu Asp Ile Ala Lys Lys Leu Val Gly Gly Ile Arg Asn Val Leu Gly Ile (OH)], while the other four have 17 residues and are classified as uperins 3 [e.g. Uperin 3.4, Gly Val Gly Asp Leu Ile Arg Lys Ala Val Ala Ala Ile Lys Asn Ile Val (NH2)]. Several of these cationic peptides have been synthesized in order for bioassays to be carried out: they show significant antibiotic activity against a range of Gram-positive microorganisms. A major skin peptide from the related species Uperoleia inundata is a powerful neuropeptide named uperin 1.1 ([Ala2] uperolein ): no corresponding neuropeptide is detected in the skin glands of Uperoleia mjobergii.

Plural Origins of Molecular Homochirality in Our Biota Part II. The Relative Stabilities of Homochiral and Mixed Oligoribotides and Peptides

1997 ◽  
Vol 52 (1-2) ◽  
pp. 89-96 ◽  
Author(s):  
Thereza Amélia Soares ◽  
Roberto Dias Lins ◽  
Ricardo Longo ◽  
Richard Garratt ◽  
Ricardo Ferreira
Keyword(s):  
Molecular Dynamics ◽  
Amino Acid ◽  
Force Field ◽  
Molecular Mechanics ◽  
Computer Simulations ◽  
The Other ◽  
Amino Acid Residues ◽  
Relative Stabilities ◽  
Amber Force Field ◽  
Cross Inhibition

Abstract By computer simulations -molecular mechanics and molecular dynamics with the amber force field (Weiner et al., (1986), J. Comp. Chem. 7, 2 30-252) -we have determined the stabilities of oligoribotide strands built with ᴅ -and ʟ-riboses, and of peptide chains with ᴅ -and ʟ-amino acid residues. In particular, complementary double-chains of oligoribotides were studied, since they are an important feature of the growing mechanism of modern nucleic acids. Peptide chains on the other hand, grow without need of a template. We found that mixed oligoribotides are less stable than homochiral ones, and that this chiral effect is less noticeable in peptide chains. The results support the interpretation that ʟ-riboses act as terminators to the template-assisted growth of oligo-r-Gᴅ (enantiomeric cross-inhibition; Joyce et al., (1987), Proc. Natl. Acad. Sci. USA 84, 4398-4402). Based on this effect, a chemical pathway is proposed which could, under assumed prebiotic conditions, bypass the hindrance of homochiral growth.

Sign in / Sign up

Export Citation Format

Share Document