scholarly journals Biochemical Characterisation of Phage Pseudomurein Endoisopeptidases PeiW and PeiP Using Synthetic Peptides

Archaea ◽  
2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
Linley R. Schofield ◽  
Amy K. Beattie ◽  
Catherine M. Tootill ◽  
Debjit Dey ◽  
Ron S. Ronimus
Keyword(s):  
Synthetic Peptide ◽  
Cell Walls ◽  
Cysteine Residue ◽  
Native Conformation ◽  
Peptide Substrates ◽  
Isopeptide Bond ◽  
Biochemical Characterisation ◽  
Methanothermobacter Marburgensis ◽  
Continuous Assay ◽  
Aerobic And Anaerobic

Pseudomurein endoisopeptidases cause lysis of the cell walls of methanogens by cleaving the isopeptide bond Ala-ε-Lys in the peptide chain of pseudomurein. PeiW and PeiP are two thermostable pseudomurein endoisopeptidases encoded by phage ΨM100 ofMethanothermobacter wolfeiand phages ΨM1 and ΨM2 ofMethanothermobacter marburgensis, respectively. A continuous assay using synthetic peptide substrates was developed and used in the biochemical characterisation of recombinant PeiW and PeiP. The advantages of these synthetic peptide substrates over natural substrates are sensitivity, high purity, and characterisation and the fact that they are more easily obtained than natural substrates. In the presence of a reducing agent, purified PeiW and PeiP each showed similar activity under aerobic and anaerobic conditions. Both enzymes required a divalent metal for activity and showed greater thermostability in the presence of Ca2+. PeiW and PeiP involve a cysteine residue in catalysis and have a monomeric native conformation. The kinetic parameters,KMandkcat, were determined, and theε-isopeptide bond between alanine and lysine was confirmed as the bond lysed by these enzymes in pseudomurein. The new assay may have wider applications for the general study of peptidases and the identification of specific methanogens susceptible to lysis by specific pseudomurein endoisopeptidases.

scholarly journals Using Synthetic Peptide Substrates to MeasureDrosophilaCaspase Activity

2015 ◽  
Vol 2015 (7) ◽  
pp. pdb.prot086231
Author(s):  
Donna Denton ◽  
Sharad Kumar
Keyword(s):  
Synthetic Peptide ◽  
Peptide Substrates

scholarly journals Extendable stapling of unprotected peptides by crosslinking two amines with o-phthalaldehyde

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Bo Li ◽  
Lan Wang ◽  
Xiangxiang Chen ◽  
Xin Chu ◽  
Hong Tang ◽  
...  
Keyword(s):  
Condensation Reaction ◽  
Cysteine Residue ◽  
Amino Groups ◽  
One Pot ◽  
Peptide Substrates ◽  
Peptide Chemistry ◽  
Peptide Modification ◽  
Wide Range ◽  
Sequential Addition ◽  
Aqueous Conditions

AbstractPeptide modification methods that do not rely on the cysteine residue are underdeveloped, and their development could greatly expand the current toolbox for peptide chemistry. During the course of preliminary investigations into the classical ortho-phthalaldehyde (OPA)-amine-thiol condensation reaction, we found that in the absence of thiol, OPA readily condenses with two primary alkyl amines to form a class of underexplored isoindolin-1-imine compounds under mild aqueous conditions. From the intramolecular version of this OPA-2amines reaction, an efficient and selective methodology using mild reaction conditions has been developed for stapling unprotected peptides via crosslinking of two amino groups in both an end-to-side and side-to-side fashion. The stapling method is superfast and broadly applicable for various peptide substrates with the reacting amino groups separated by a wide range of different amino acid units. The macrocyclization reactions of selected substrates are completed within 10 seconds at 5 mM concentration and within 2 minutes at 50 μM concentration. Importantly, the resulting cyclized peptides with an isoindolinimine linkage can be extended in a one-pot sequential addition manner with several different electron-deficient π electrophiles, thereby generating more complex structures.

Vitamin K Dependent Carboxylaticn Of Peptide Bound Glutamic Acid Residues

1981 ◽  
Author(s):  
D P Kosow ◽  
M P Esnouf ◽  
A I Gainey ◽  
H A O Hill ◽  
P J Thornally
Keyword(s):  
Carbon Dioxide ◽  
Glutamic Acid ◽  
Rat Liver ◽  
Vitamin K ◽  
Active Carbon ◽  
Synthetic Peptide ◽  
Alcoholic Solution ◽  
Chemical Mechanism ◽  
Peptide Substrates ◽  
Rapid Formation

The chemical mechanism by which vitamin K promotes the posttranslational carboxylation of specific glutamic acid residues in the N-terminal region of prothrombin has not yet been elucidated. We have previously suggested that vitamin K reacts with dioxygen and carbon dioxide to form a species of active carbon. In this study we have investigated the reaction of reduced vitamin K in alcoholic solution with dioxygen in the presence and absence of carbon dioxide. We find that carbon dioxide is necessary for the rapid formation of vitamin K oxide. Vitamin K oxide was formed when either cis or trans vitamin K was used. However, trans vitamin K is specifically required in enzymatic carboxylation studies. We propose that in rat liver microsomal preparations the carboxylation of synthetic peptide substrates is coupled to the chemical epoxidation of vitamin K by the carboxylase.

scholarly journals LambdaSa1 and LambdaSa2 Prophage Lysins of Streptococcus agalactiae

2007 ◽  
Vol 73 (22) ◽  
pp. 7150-7154 ◽  
Author(s):  
David G. Pritchard ◽  
Shengli Dong ◽  
Marion C. Kirk ◽  
Robert T. Cartee ◽  
John R. Baker
Keyword(s):  
Escherichia Coli ◽  
Staphylococcus Aureus ◽  
Cell Wall ◽  
Streptococcus Agalactiae ◽  
Synthetic Peptide ◽  
Cell Walls ◽  
Peptide Substrate ◽  
Amidase Activity ◽  
Cleavage Specificity ◽  
Endopeptidase Activity

ABSTRACT Putative N-acetylmuramyl-l-alanine amidase genes from LambdaSa1 and LambdaSa2 prophages of Streptococcus agalactiae were cloned and expressed in Escherichia coli. The purified enzymes lysed the cell walls of Streptococcus agalactiae, Streptococcus pneumoniae, and Staphylococcus aureus. The peptidoglycan digestion products in the cell wall lysates were not consistent with amidase activity. Instead, the structure of the muropeptide digestion fragments indicated that both the LambdaSa1 and LambdaSa2 lysins exhibited γ-d-glutaminyl-l-lysine endopeptidase activity. The endopeptidase cleavage specificity of the lysins was confirmed using a synthetic peptide substrate corresponding to a portion of the stem peptide and cross bridge of Streptococcus agalactiae peptidoglycan. The LambdaSa2 lysin also displayed β-d-N-acetylglucosaminidase activity.

90 Characterisation of an HCV NS3/NS4A proteinase fusion protein expressed in E.coli using synthetic peptide substrates

1997 ◽  
Vol 25 (4) ◽  
pp. S624-S624 ◽  
Author(s):  
TREVOR C.I. WILKINSON ◽  
PETER R. BUNYARD ◽  
KATHLEEN QUIRK ◽  
CLAIRE S. WILKINSON
Keyword(s):  
Fusion Protein ◽  
Synthetic Peptide ◽  
Peptide Substrates

scholarly journals Reaction of a tumour-associated trypsin inhibitor with serine proteinases associated with coagulation and tumour invasion

1988 ◽  
Vol 254 (3) ◽  
pp. 911-914 ◽  
Author(s):  
U Turpeinen ◽  
E Koivunen ◽  
U H Stenman
Keyword(s):  
Plasminogen Activator ◽  
Tissue Plasminogen Activator ◽  
Trypsin Inhibitor ◽  
Synthetic Peptide ◽  
Serine Proteinases ◽  
Tumour Invasion ◽  
Peptide Substrates ◽  
Tissue Plasminogen

The inhibition of six serine proteinases by a tumour-associated trypsin inhibitor (TATI) was studied using synthetic peptide substrates. Physiological concentrations of TATI inhibited the amidolytic activities of trypsin, plasmin, urokinase and tissue plasminogen activator (tPA). Chymotrypsin, kallikrein and thrombin were also inhibited, but by much higher concentrations of TATI. The ability of TATI to inhibit trypsin, plasmin, urokinase and tPA suggests that it has a role in proteolytic processes in vivo involving these enzymes.

Characterization of Synthetic Peptide Substrates for p34cdc2 Protein Kinase

1991 ◽  
Vol 45 (4) ◽  
pp. 391-400 ◽  
Author(s):  
Daniel R. Marshak ◽  
Mark T. Vandenberg ◽  
Young Seuk Bae ◽  
Ii Je Yu
Keyword(s):  
Protein Kinase ◽  
Synthetic Peptide ◽  
Peptide Substrates
Sign in / Sign up

Export Citation Format

Share Document