scholarly journals Solution Structure of Acidocin B, a Circular Bacteriocin Produced by Lactobacillus acidophilus M46

2015 ◽  
Vol 81 (8) ◽  
pp. 2910-2918 ◽  
Author(s):  
Jeella Z. Acedo ◽  
Marco J. van Belkum ◽  
Christopher T. Lohans ◽  
Ryan T. McKay ◽  
Mark Miskolzie ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Lactobacillus Acidophilus ◽  
Solution Structure ◽  
Sequence Similarity ◽  
Sodium Dodecyl ◽  
Three Dimensional ◽  
Peptide Sequence ◽  
Dimensional Structure ◽  
Content Type ◽  
Circular Bacteriocin

ABSTRACTAcidocin B, a bacteriocin produced byLactobacillus acidophilusM46, was originally reported to be a linear peptide composed of 59 amino acid residues. However, its high sequence similarity to gassericin A, a circular bacteriocin fromLactobacillus gasseriLA39, suggested that acidocin B might be circular as well. Acidocin B was purified from culture supernatant by a series of hydrophobic interaction chromatographic steps. Its circular nature was ascertained by matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) mass spectrometry and tandem mass spectrometry (MS/MS) sequencing. The peptide sequence was found to consist of 58 amino acids with a molecular mass of 5,621.5 Da. The sequence of the acidocin B biosynthetic gene cluster was also determined and showed high nucleotide sequence similarity to that of gassericin A. The nuclear magnetic resonance (NMR) solution structure of acidocin B in sodium dodecyl sulfate micelles was elucidated, revealing that it is composed of four α-helices of similar length that are folded to form a compact, globular bundle with a central pore. This is a three-dimensional structure for a member of subgroup II circular bacteriocins, which are classified based on their isoelectric points of ∼7 or lower. Comparison of acidocin B with carnocyclin A, a subgroup I circular bacteriocin with four α-helices and a pI of 10, revealed differences in the overall folding. The observed variations could be attributed to inherent diversity in their physical properties, which also required the use of different solvent systems for three-dimensional structural elucidation.

scholarly journals Conformation and membrane interaction studies of the potent antimicrobial and anticancer peptide palustrin-Ca

2021 ◽  
Author(s):  
Patrick Brendan Timmons ◽  
Chandralal M Hewage
Keyword(s):  
Sodium Dodecyl ◽  
Three Dimensional ◽  
Dynamics Simulation ◽  
Peptide Sequence ◽  
Helical Conformation ◽  
Dimensional Structure ◽  
Amino Acid Residues ◽  
Anticancer Activities ◽  
American Bullfrog ◽  
Α Helix

Palustrin-Ca (GFLDIIKDTGKEFAVKILNNLKCKLAGGCPP) is a host defense peptide with potent antimicrobial and anticancer activities, first isolated from the skin of the American bullfrog Lithobates catesbeianus. The peptide is 31 amino acid residues long, cationic and amphipathic. Two-dimensional NMR spectroscopy was employed to characterise its three-dimensional structure in a 50/50% water/2,2,2-trifluoroethanol-d3 mixture. The structure is defined by an α-helix that spans between Ile6-Ala26, and a cyclic disulphide bridged domain at the C-terminal end of the peptide sequence, between residues 23 and 29. A molecular dynamics simulation was employed to model the peptide's interactions with sodium dodecyl sulphate micelles, a widely used bacterial membrane-mimicking environment. Throughout the simulation, the peptide was found to maintain its α-helical conformation between residues Ile6-Ala26, while adopting a position parallel to the surface to micelle, which is energetically-favourable due to many hydrophobic and electrostatic contacts with the micelle.

scholarly journals Conformation and membrane interaction studies of the potent antimicrobial and anticancer peptide palustrin-Ca

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Patrick B. Timmons ◽  
Chandralal M. Hewage
Keyword(s):  
Sodium Dodecyl ◽  
Three Dimensional ◽  
Dynamics Simulation ◽  
Peptide Sequence ◽  
Helical Conformation ◽  
Dimensional Structure ◽  
Amino Acid Residues ◽  
Anticancer Activities ◽  
Anticancer Peptide ◽  
American Bullfrog

AbstractPalustrin-Ca (GFLDIIKDTGKEFAVKILNNLKCKLAGGCPP) is a host defence peptide with potent antimicrobial and anticancer activities, first isolated from the skin of the American bullfrog Lithobates catesbeianus. The peptide is 31 amino acid residues long, cationic and amphipathic. Two-dimensional NMR spectroscopy was employed to characterise its three-dimensional structure in a 50/50% water/2,2,2-trifluoroethanol-$$d_{3}$$ d 3 mixture. The structure is defined by an $$\alpha$$ α -helix that spans between Ile$$^{6}$$ 6 -Ala$$^{26}$$ 26 , and a cyclic disulfide-bridged domain at the C-terminal end of the peptide sequence, between residues 23 and 29. A molecular dynamics simulation was employed to model the peptide’s interactions with sodium dodecyl sulfate micelles, a widely used bacterial membrane-mimicking environment. Throughout the simulation, the peptide was found to maintain its $$\alpha$$ α -helical conformation between residues Ile$$^{6}$$ 6 -Ala$$^{26}$$ 26 , while adopting a position parallel to the surface to micelle, which is energetically-favourable due to many hydrophobic and electrostatic contacts with the micelle.

scholarly journals An Intramolecular Salt Bridge in Bacillus thuringiensis Cry4Ba Toxin Is Involved in the Stability of Helix α-3, Which Is Needed for Oligomerization and Insecticidal Activity

2017 ◽  
Vol 83 (20) ◽  
Author(s):  
Sabino Pacheco ◽  
Isabel Gómez ◽  
Jorge Sánchez ◽  
Blanca-Ines García-Gómez ◽  
Mario Soberón ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Double Point ◽  
Single Point ◽  
Three Dimensional ◽  
Point Mutations ◽  
Salt Bridge ◽  
Dimensional Structure ◽  
Cry Toxins ◽  
Content Type ◽  
Domain I

ABSTRACT Bacillus thuringiensis three-domain Cry toxins kill insects by forming pores in the apical membrane of larval midgut cells. Oligomerization of the toxin is an important step for pore formation. Domain I helix α-3 participates in toxin oligomerization. Here we identify an intramolecular salt bridge within helix α-3 of Cry4Ba (D111-K115) that is conserved in many members of the family of three-domain Cry toxins. Single point mutations such as D111K or K115D resulted in proteins severely affected in toxicity. These mutants were also altered in oligomerization, and the mutant K115D was more sensitive to protease digestion. The double point mutant with reversed charges, D111K-K115D, recovered both oligomerization and toxicity, suggesting that this salt bridge is highly important for conservation of the structure of helix α-3 and necessary to promote the correct oligomerization of the toxin. IMPORTANCE Domain I has been shown to be involved in oligomerization through helix α-3 in different Cry toxins, and mutations affecting oligomerization also elicit changes in toxicity. The three-dimensional structure of the Cry4Ba toxin reveals an intramolecular salt bridge in helix α-3 of domain I. Mutations that disrupt this salt bridge resulted in changes in Cry4Ba oligomerization and toxicity, while a double point reciprocal mutation that restored the salt bridge resulted in recovery of toxin oligomerization and toxicity. These data highlight the role of oligomer formation as a key step in Cry4Ba toxicity.

scholarly journals Identification, Characterization, and Three-Dimensional Structure of the Novel Circular Bacteriocin, Enterocin NKR-5-3B, fromEnterococcus faecium

Biochemistry ◽  
2015 ◽  
Vol 54 (31) ◽  
pp. 4863-4876 ◽  
Author(s):  
Kohei Himeno ◽  
K. Johan Rosengren ◽  
Tomoko Inoue ◽  
Rodney H. Perez ◽  
Michelle L. Colgrave ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Dimensional Structure ◽  
The Novel ◽  
Three Dimensional Structure ◽  
Circular Bacteriocin

scholarly journals BLASTing away preconceptions in crystallization trials

2019 ◽  
Vol 75 (3) ◽  
pp. 184-192 ◽  
Author(s):  
Gabriel Jan Abrahams ◽  
Janet Newman
Keyword(s):  
Protein Data Bank ◽  
Sequence Similarity ◽  
Three Dimensional ◽  
Protein Sequences ◽  
Protein Molecule ◽  
Data Bank ◽  
Dimensional Structure ◽  
Critical Step ◽  
Quantitative Verification ◽  
Better Than

Crystallization is in many cases a critical step for solving the three-dimensional structure of a protein molecule. Determining which set of chemicals to use in the initial screen is typically agnostic of the protein under investigation; however, crystallization efficiency could potentially be improved if this were not the case. Previous work has assumed that sequence similarity may provide useful information about appropriate crystallization cocktails; however, the authors are not aware of any quantitative verification of this assumption. This research investigates whether, given current information, one can detect any correlation between sequence similarity and crystallization cocktails. BLAST was used to quantitate the similarity between protein sequences in the Protein Data Bank, and this was compared with three estimations of the chemical similarities of the respective crystallization cocktails. No correlation was detected between proteins of similar (but not identical) sequence and their crystallization cocktails, suggesting that methods of determining screens based on this assumption are unlikely to result in screens that are better than those currently in use.

scholarly journals DUF3380 Domain from a Salmonella Phage Endolysin Shows PotentN-Acetylmuramidase Activity

2016 ◽  
Vol 82 (16) ◽  
pp. 4975-4981 ◽  
Author(s):  
Lorena Rodríguez-Rubio ◽  
Hans Gerstmans ◽  
Simon Thorpe ◽  
Stéphane Mesnage ◽  
Rob Lavigne ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Thermal Resistance ◽  
High Performance ◽  
Antimicrobial Agents ◽  
Biochemical Characterization ◽  
Specific Activity ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Gram Negative ◽  
Content Type

ABSTRACTBacteriophage-encoded endolysins are highly diverse enzymes that cleave the bacterial peptidoglycan layer. Current research focuses on their potential applications in medicine, in food conservation, and as biotechnological tools. Despite the wealth of applications relying on the use of endolysin, little is known about the enzymatic properties of these enzymes, especially in the case of endolysins of bacteriophages infecting Gram-negative species. Automated genome annotations therefore remain to be confirmed. Here, we report the biochemical analysis and cleavage site determination of a novelSalmonellabacteriophage endolysin, Gp110, which comprises an uncharacterizeddomain ofunknownfunction (DUF3380; pfam11860) in its C terminus and shows a higher specific activity (34,240 U/μM) than that of 14 previously characterized endolysins active against peptidoglycan from Gram-negative bacteria (corresponding to 1.7- to 364-fold higher activity). Gp110 is a modular endolysin with an optimal pH of enzymatic activity of pH 8 and elevated thermal resistance. Reverse-phase high-performance liquid chromatography (RP-HPLC) analysis coupled to mass spectrometry showed that DUF3380 hasN-acetylmuramidase (lysozyme) activity cleaving the β-(1,4) glycosidic bond betweenN-acetylmuramic acid andN-acetylglucosamine residues. Gp110 is active against directly cross-linked peptidoglycans with various peptide stem compositions, making it an attractive enzyme for developing novel antimicrobial agents.IMPORTANCEWe report the functional and biochemical characterization of theSalmonellaphage endolysin Gp110. This endolysin has a modular structure with an enzymatically active domain and a cell wall binding domain. The enzymatic activity of this endolysin exceeds that of all other endolysins previously characterized using the same methods. A domain of unknown function (DUF3380) is responsible for this high enzymatic activity. We report that DUF3380 hasN-acetylmuramidase activity against directly cross-linked peptidoglycans with various peptide stem compositions. This experimentally verified activity allows better classification and understanding of the enzymatic activities of endolysins, which mostly are inferred by sequence similarities. Three-dimensional structure predictions for Gp110 suggest a fold that is completely different from that of known structures of enzymes with the same peptidoglycan cleavage specificity, making this endolysin quite unique. All of these features, combined with increased thermal resistance, make Gp110 an attractive candidate for engineering novel endolysin-based antibacterials.

Liquid chromatography mass spectrometry based characterization of epitope configurations

2020 ◽  
Vol 12 (45) ◽  
pp. 5476-5484
Author(s):  
Maren Christin Stillesby Levernæs ◽  
Arelí Urtubia Moe ◽  
Sigurd Leinæs Bøe ◽  
Elisabeth Paus ◽  
Léon Reubsaet ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Liquid Chromatography ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Liquid Chromatography Mass Spectrometry ◽  
Three Dimensional Structure ◽  
Chromatography Mass Spectrometry ◽  
Pre Treatment

Here we evaluate a quick and easy tool for determination of epitope configuration using immunocapture and liquid chromatography mass spectrometry (LC-MS) subsequent to pre-treatment of the target protein to disrupt its three-dimensional structure.

Hospitality situations, consumer expertise, and perceptions of wine attributes: three empirical studies

2019 ◽  
Vol 31 (1) ◽  
pp. 68-88 ◽  
Author(s):  
Dale F. Duhan ◽  
Shannon B. Rinaldo ◽  
Natalia Velikova ◽  
Tim Dodd ◽  
Brent Trela
Keyword(s):  
Empirical Studies ◽  
Three Dimensional ◽  
Total Sample ◽  
Dimensional Structure ◽  
Product Knowledge ◽  
Product Attributes ◽  
Content Type ◽  
Wine Consumption ◽  
Consumer Expertise ◽  
Academic Researchers

PurposeWine choices are not always fully understood by academic researchers or the industry. This paper aims to outline and test a theoretical model proposing that wine consumption may be dependent on differences in consumer expertise, the hospitality situation, characteristics of the wine itself and an interaction of these variables.Design/methodology/approachThree empirical studies (total sample size = 356) tested these theoretical propositions. Consumers with varying levels of wine knowledge were presented with experimental vignettes showing videos of wine opening and pouring and were asked to pair wines with hospitality situations.FindingsStudy 1 found that consumers with low product knowledge were more sensitive to hospitality situations and extrinsic product attributes (closures) than were the experts. Study 2 found that wine hospitality situations fall into three predicted categories, namely, food, friends and formality, although contrary to prediction, the presence of food was the weakest predictors. Study 3 demonstrated the robustness of the three-dimensional structure of wine hospitality situations.Practical implicationsThese studies provided important practical information because targeting various market segments requires the industry to know what product attributes are favored by different groups of consumers different situations.Originality/valuePrevious researchers have discussed the difficulty of measuring consumption situations. By limiting these studies to wine consumption within hospitality situations, the authors learned much about how consumers’ characteristics, product attributes and the situations interact to influence not only product assessments but also choices.

scholarly journals Solution structure of the strawberry allergen Fra a 1

2012 ◽  
Vol 32 (6) ◽  
pp. 567-575 ◽  
Author(s):  
Christian Seutter von Loetzen ◽  
Kristian Schweimer ◽  
Wilfried Schwab ◽  
Paul Rösch ◽  
Olivia Hartl-Spiegelhauer
Keyword(s):  
Solution Structure ◽  
Three Dimensional ◽  
Protein Family ◽  
Dimensional Structure ◽  
Hydrophobic Pocket ◽  
Pigment Synthesis ◽  
Family Protein ◽  
Pr10 Protein ◽  
Α Helix

The PR10 family protein Fra a 1E from strawberry (Fragaria x ananassa) is down-regulated in white strawberry mutants, and transient RNAi (RNA interference)-mediated silencing experiments confirmed that Fra a 1 is involved in fruit pigment synthesis. In the present study, we determined the solution structure of Fra a 1E. The protein fold is identical with that of other members of the PR10 protein family and consists of a seven-stranded antiparallel β-sheet, two short V-shaped α-helices and a long C-terminal α-helix that encompass a hydrophobic pocket. Whereas Fra a 1E contains the glycine-rich loop that is highly conserved throughout the protein family, the volume of the hydrophobic pocket and the size of its entrance are much larger than expected. The three-dimensional structure may shed some light on its physiological function and may help to further understand the role of PR10 proteins in plants.

Sign in / Sign up

Export Citation Format

Share Document