scholarly journals Posttranslational isoprenylation of tryptophan in bacteria

2017 ◽  
Vol 13 ◽  
pp. 338-346 ◽  
Author(s):  
Masahiro Okada ◽  
Tomotoshi Sugita ◽  
Ikuro Abe
Keyword(s):  
Quorum Sensing ◽  
Cyclic Peptide ◽  
Cysteine Residues ◽  
Tryptophan Residue ◽  
Biosynthetic Pathways ◽  
Thiol Groups ◽  
Tryptophan Residues ◽  
Peptide Pheromone

Posttranslational isoprenylation is generally recognized as a universal modification of the cysteine residues in peptides and the thiol groups of proteins in eukaryotes. In contrast, the Bacillus quorum sensing peptide pheromone, the ComX pheromone, possesses a posttranslationally modified tryptophan residue, and the tryptophan residue is isoprenylated with either a geranyl or farnesyl group at the gamma position to form a tricyclic skeleton that bears a newly formed pyrrolidine, similar to proline. The post-translational dimethylallylation of two tryptophan residues of a cyclic peptide, kawaguchipeptin A, from cyanobacteria has also been reported. Interestingly, the modified tryptophan residues of kawaguchipeptin A have the same scaffold as that of the ComX pheromones, but with the opposite stereochemistry. This review highlights the biosynthetic pathways and posttranslational isoprenylation of tryptophan. In particular, recent studies on peptide modifying enzymes are discussed.

scholarly journals Chemical modification of cellulase from Aspergillus niger

1977 ◽  
Vol 167 (3) ◽  
pp. 549-556 ◽  
Author(s):  
P L Hurst ◽  
P A Sullivan ◽  
M G Shepherd
Keyword(s):  
Ph Dependence ◽  
Cellulase Activity ◽  
Tryptophan Residue ◽  
Carboxyl Group ◽  
Enzyme Molecule ◽  
Thiol Groups ◽  
Original Activity ◽  
Activity Inhibition ◽  
Tryptophan Residues ◽  
Benzyl Halides

N-Bromosuccinimide completely inactivated the cellulase, and titration experiments showed that oxidation of one tryptophan residue per cellulase molecule coincided with 100% inactivation. CM-cellulose protected the enzyme from inactivation by N-bromosuccinimide. The cellulase was inhibited by active benzyl halides, and reaction with 2-hydroxy-5-nitrobenzyl bromide resulted in the incorporation of 2.3 hydroxy-5-nitrobenzyl groups per enzyme molecule; one tryptophan residue was shown to be essential for activity. Diazocarbonyl compounds in the presence of Cu2+ ions inhibited the enzyme. The pH-dependence of inactivation was consistent with the reaction occurring with a protonated carboxyl group. Carbodi-imide inhibited the cellulase, and kinetic analysis indicated that there was an average of 1 mol of carbodi-imide binding to the cellulase during inactivation. Treatment of the cellulase with diethyl pyrocarbonate resulted in the modification of two out of the four histidine residues present in the cellulase. The modified enzyme retained 40% of its original activity. Inhibition of cellulase activity by the metal ions Ag+ and Hg2+ was ascribed to interaction with tryptophan residues, rather than with thiol groups.

scholarly journals Preparation of Cyclic Peptide Alkaloids Containing Functionalized Tryptophan Residues

2006 ◽  
Vol 1 (10) ◽  
pp. 1934578X0600101
Author(s):  
Alexander K. L. Yuen ◽  
Craig A. Hutton
Keyword(s):  
Natural Products ◽  
Cyclic Peptide ◽  
The Novel ◽  
Diazonamide A ◽  
The Core ◽  
Tryptophan Residues ◽  
Novel Methods

This review covers the synthesis of various cyclic peptide natural products possessing highly functionalized tryptophan residues, focusing on the examples of diazonamide A, the TMC-95 compounds, the celogentin/moroidin family and the complestatin/chloropeptin system. Recent efforts toward the preparation of these modified-tryptophan-containing peptides will be outlined, focusing primarily on the novel methods for the assembly of the highly functionalized indole/tryptophan moieties at the core of these structures.

Fluorescent Properties of Firefly Luciferases and Their Complexes with Luciferin

2000 ◽  
Vol 20 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Ekaterina I. Dementieva ◽  
Elena A. Fedorchuk ◽  
Lubov Yu. Brovko ◽  
Alexander P. Savitskii ◽  
Natalya N. Ugarova
Keyword(s):  
Energy Transfer ◽  
Tryptophan Fluorescence ◽  
Tryptophan Residue ◽  
Amino Acid Residues ◽  
Photinus Pyralis ◽  
Fluorescent Properties ◽  
Effective Energy Transfer ◽  
Tryptophan Residues ◽  
Luciola Mingrelica

Fluorescence of luciferases from Luciola mingrelica (single tryptophanresidue, Trp-419) and Photinus pyralis (two tryptophan residues, Trp-417,Trp-426) was studied. Analysis of quenching of tryptophan fluorescenceshowed that the tryptophan residue conserved in all luciferases is notaccessible for charged quenchers, which is explained by the presence ofpositively and negatively charged amino acid residues in the close vicinityto it. An effective energy transfer from tryptophan to luciferin wasobserved during quenching of tryptophan fluorescence of both luciferaseswith luciferin. From the data on the energy transfer, the distance betweenthe luciferin molecule and Trp-417 (419) in the luciferin–luciferasecomplex was calculated: 11–15 Å for P. pyralis and 12–17Å for L. mingrelica luciferases. The role of the conserved Trp residuein the catalysis is discussed.

scholarly journals Membrane insertion of the N-terminal α-helix of equinatoxin II, a sea anemone cytolytic toxin

2004 ◽  
Vol 384 (2) ◽  
pp. 421-428 ◽  
Author(s):  
Ion GUTIÉRREZ-AGUIRRE ◽  
Ariana BARLIČ ◽  
Zdravko PODLESEK ◽  
Peter MAČEK ◽  
Gregor ANDERLUH ◽  
...  
Keyword(s):  
Lipid Membranes ◽  
Lipid Membrane ◽  
Model Systems ◽  
Tryptophan Residue ◽  
Sea Anemones ◽  
Fluorescence Measurements ◽  
Tryptophan Residues ◽  
Equinatoxin Ii ◽  
Α Helix ◽  
Pore Forming Proteins

Equinatoxin II (Eqt-II) is a member of the actinoporins, a unique family of cytotoxins comprising 20 kDa pore-forming proteins isolated from sea anemones. Actinoporins bind preferentially to lipid membranes containing sphingomyelin, and create cation-selective pores by oligomerization of three to four monomers. Previous studies have shown that regions of Eqt-II crucial for its cytolytic mechanism are an exposed aromatic cluster and the N-terminal region containing an amphipathic α-helix. In the present study, we have investigated the transfer of the N-terminal α-helix into the lipid membrane by the use of three mutants containing an additional tryptophan residue in different positions within the amphipathic α-helix (Ile18→Trp, Val22→Trp and Ala25→Trp). The interaction of the mutants with different model systems, such as lipid monolayers, erythrocytes and ghost membranes, was extensively characterized. Intrinsic fluorescence measurements and the use of vesicles containing brominated phospholipids indicated a deep localization of the N-terminal amphipathic helix in the lipid bilayer, except for the case of Val22→Trp. This mutant is stabilized in a state immediately prior to final pore formation. The introduction of additional tryptophan residues in the sequence of Eqt-II has proved to be a suitable approach to monitor the new environments that surround defined regions of the molecule upon membrane interaction.

scholarly journals The Formation of Streptococcus mutans Persisters Induced by the Quorum-Sensing Peptide Pheromone Is Affected by the LexA Regulator

2015 ◽  
Vol 197 (6) ◽  
pp. 1083-1094 ◽  
Author(s):  
Vincent Leung ◽  
Dragana Ajdic ◽  
Stephanie Koyanagi ◽  
Céline M. Lévesque
Keyword(s):  
Quorum Sensing ◽  
Streptococcus Mutans ◽  
Bacterial Species ◽  
Regulatory System ◽  
Bacterial Survival ◽  
Chronic Infections ◽  
Persister Cells ◽  
Gene Encoding ◽  
Content Type ◽  
Peptide Pheromone

The presence of multidrug-tolerant persister cells within microbial populations has been implicated in the resiliency of bacterial survival against antibiotic treatments and is a major contributing factor in chronic infections. The mechanisms by which these phenotypic variants are formed have been linked to stress response pathways in various bacterial species, but many of these mechanisms remain unclear. We have previously shown that in the cariogenic organismStreptococcus mutans, the quorum-sensing peptide CSP (competence-stimulating peptide) pheromone was a stress-inducible alarmone that triggered an increased formation of multidrug-tolerant persisters. In this study, we characterized SMU.2027, a CSP-inducible gene encoding a LexA ortholog. We showed that in addition to exogenous CSP exposure, stressors, including heat shock, oxidative stress, and ofloxacin antibiotic, were capable of triggering expression oflexAin an autoregulatory manner akin to that of LexA-like transcriptional regulators. We demonstrated the role of LexA and its importance in regulating tolerance toward DNA damage in a noncanonical SOS mechanism. We showed its involvement and regulatory role in the formation of persisters induced by the CSP-ComDE quorum-sensing regulatory system. We further identified key genes involved in sugar and amino acid metabolism, the clustered regularly interspaced short palindromic repeat (CRISPR) system, and autolysin from transcriptomic analyses that contribute to the formation of quorum-sensing-induced persister cells.

scholarly journals Thiol-Modification as Important Mode of Action for Allicin from Garlic (Allium sativum)

Proceedings ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 27 ◽  
Author(s):  
Martin C. H. Gruhlke
Keyword(s):  
Molecular Weight ◽  
Biological Activity ◽  
Active Compound ◽  
Mode Of Action ◽  
Allium Sativum ◽  
Cysteine Residues ◽  
Low Molecular Weight ◽  
Thiol Groups ◽  
Ancient Times ◽  
In Cells

Garlic is a common ingredient in food, normally used as spice but is also used since ancient times for its health beneficial activity. The thiosulfinate allicin is the first active compound in freshly damaged garlic tissue and reacts with thiol-groups. Hence, allicin is able to modify thiol groups, both of protein cysteine-residues and low-molecular weight thiols like glutathione. This thiol-modification is supposed to be an important mechanism for allicin’s biological activity. Here, the mechanisms and possible targets for allicin in cells are discussed.

Preparation of Cyclic Peptide Alkaloids Containing Functionalized Tryptophan Residues

ChemInform ◽  
2007 ◽  
Vol 38 (38) ◽  
Author(s):  
Alexander K. L. Yuen ◽  
Craig A. Hutton
Keyword(s):  
Cyclic Peptide ◽  
Tryptophan Residues

scholarly journals Interactions between apo-(d-β-hydroxybutyrate dehydrogenase) and phospholipids studied by intrinsic and extrinsic fluorescence

1986 ◽  
Vol 237 (2) ◽  
pp. 359-364 ◽  
Author(s):  
M S el Kebbaj ◽  
N Latruffe ◽  
M Monsigny ◽  
A Obrenovitch
Keyword(s):  
Conformational Changes ◽  
Negative Charge ◽  
Positive Charge ◽  
Tryptophan Residue ◽  
Fluorescence Energy Transfer ◽  
Hydrophobic Region ◽  
Phospholipid Liposomes ◽  
Tryptophan Residues ◽  
Beta Hydroxybutyrate ◽  
Fluorescence Energy

Interactions of D-beta-hydroxybutyrate dehydrogenase with phospholipids were investigated by both intrinsic- and extrinsic-fluorescence approaches. The intrinsic fluorescence, mainly caused by tryptophan residues, increased upon re-activation in the presence of phospholipids bearing a positive charge, i.e. phosphatidylcholine, but decreased in the presence of non-re-activating phospholipids with a negative charge. This indicates either that the environment of tryptophan residues is affected by charges rather than by hydrophobic chains of phospholipids, or that the enzyme undergoes different conformational changes depending on the nature of the phospholipids. On the other hand, the graph of the temperature-dependence of the fluorescence intensities of the enzyme embedded in dimyristoylphosphatidylcholine liposomes exhibits a break around 21 degrees C. This indicates either that at least one tryptophan residue is closely in contact with the hydrophobic chains of phospholipids or that there is a change in the environment of tryptophan residues owing to the physical state of the phospholipids. The addition of D-beta-hydroxybutyrate apo-dehydrogenase to phospholipid liposomes containing diphenylhexatriene (a fluorescent probe) increased the diphenylhexatriene fluorescence polarization. Moreover, there was a partial fluorescence energy transfer from tryptophan to diphenylhexatriene. These results strongly favour the possibility that there is a portion of the enzyme polypeptide chain inserted into the phospholipid hydrophobic region. All these results demonstrate that D-beta-hydroxybutyrate apo-dehydrogenase interacts with both polar and hydrophobic parts of phospholipids and leads to small, but essential, conformational changes of the enzyme.

scholarly journals Studies on the biotin-binding site of streptavidin. Tryptophan residues involved in the active site

1988 ◽  
Vol 256 (1) ◽  
pp. 279-282 ◽  
Author(s):  
G Gitlin ◽  
E A Bayer ◽  
M Wilchek
Keyword(s):  
Binding Site ◽  
Reversed Phase ◽  
Binding Activity ◽  
Complete Loss ◽  
Tryptophan Residue ◽  
Tryptophan Residues ◽  
Lysine Residues ◽  
Biotin Binding ◽  
Peptide Fractions ◽  
Specific Reagent

Streptavidin, the non-glycosylated bacterial analogue of the egg-white glycoprotein avidin, was modified with the tryptophan-specific reagent 2-hydroxy-5-nitrobenzyl (Hnb) bromide. As with avidin, complete loss of biotin-binding activity was achieved upon modification of an average of one tryptophan residue per streptavidin subunit. Tryptic peptides obtained from an Hnb-modified streptavidin preparation were fractionated by reversed-phase h.p.l.c., and three major Hnb-containing peptide fractions were isolated. Amino acid and N-terminal sequence analysis revealed that tryptophan residues 92, 108 and 120 are modified and probably comprise part of the biotin-binding site of the streptavidin molecule. Unlike avidin, the modification of lysine residues in streptavidin failed to result in complete loss of biotin-binding activity. The data imply subtle differences in the fine structure of the respective biotin-binding sites of the two proteins.

Structure of the Bacillus subtilis quorum-sensing peptide pheromone ComX

2005 ◽  
Vol 1 (1) ◽  
pp. 23-24 ◽  
Author(s):  
Masahiro Okada ◽  
Isao Sato ◽  
Soo Jeong Cho ◽  
Hidehisa Iwata ◽  
Toshihiko Nishio ◽  
...  
Keyword(s):  
Bacillus Subtilis ◽  
Quorum Sensing ◽  
Peptide Pheromone
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