New Methods in Electron Microscopy Help Elucidate the Structure of the Murein Sacculus and the Distribution of Penicillin-Binding Proteins

1993 ◽  
pp. 57-69 ◽  
Author(s):  
Terry J. Beveridge
Keyword(s):  
Electron Microscopy ◽  
Binding Proteins ◽  
Penicillin Binding Proteins ◽  
New Methods ◽  
Murein Sacculus

scholarly journals Mechanism of β-Lactam Action in Streptococcus pneumoniae: the Piperacillin Paradox

2014 ◽  
Vol 59 (1) ◽  
pp. 609-621 ◽  
Author(s):  
Jules Philippe ◽  
Benoit Gallet ◽  
Cécile Morlot ◽  
Dalia Denapaite ◽  
Regine Hakenbeck ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Streptococcus Pneumoniae ◽  
Mode Of Action ◽  
Time Course ◽  
Binding Proteins ◽  
Epifluorescence Microscopy ◽  
Human Pathogen ◽  
Content Type ◽  
Penicillin Binding Proteins

ABSTRACTThe human pathogenStreptococcus pneumoniaehas been treated for decades with β-lactam antibiotics. Its resistance is now widespread, mediated by the expression of mosaic variants of the target enzymes, the penicillin-binding proteins (PBPs). Understanding the mode of action of β-lactams, not only in molecular detail but also in their physiological consequences, will be crucial to improving these drugs and any counterresistances. In this work, we investigate the piperacillin paradox, by which this β-lactam selects primarily variants of PBP2b, whereas its most reactive target is PBP2x. These PBPs are both essential monofunctional transpeptidases involved in peptidoglycan assembly. PBP2x participates in septal synthesis, while PBP2b functions in peripheral elongation. The formation of the “lemon”-shaped cells induced by piperacillin treatment is consistent with the inhibition of PBP2x. Following the examination of treated and untreated cells by electron microscopy, the localization of the PBPs by epifluorescence microscopy, and the determination of the inhibition time course of the different PBPs, we propose a model of peptidoglycan assembly that accounts for the piperacillin paradox.

Investigating the role of phytochemicals in silver nanoparticle as an antibacterial agent using computational and experimental analysis

2021 ◽  
Vol 16 (12) ◽  
pp. 100-108
Author(s):  
Akanksha Dubey ◽  
Jayanthi Sivaraman
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Binding Proteins ◽  
Chemical Constituents ◽  
Experimental Studies ◽  
Antibacterial Properties ◽  
Bacterial Strains ◽  
Penicillin Binding Proteins ◽  
Synthesis Of Nanoparticles

Designing a powerful approach for the synthesis of metal nanoparticles is a critical footstep in the field of nanotechnology. Algae-mediated synthesis of nanoparticles is a substitute to overthrow the restrictions of traditional methods. Penicillin-binding proteins are proteins binding to β-lactams and are convoluted in cell wall biosynthesis. The present study aimed to investigate the potential role of phytochemicals in inhibiting these penicillin binding proteins against bacterial agents using computational and experimental studies. Biosynthesis of silver nanoparticles was done using aqueous extract of Dictyota bartayresiana and was evaluated for antibacterial activity. Characterization was done via UV-visible spectroscopy, Scanning electron microscopy, Transmission electron microscopy and Xray diffraction studies. It was found that synthesized nanoparticle was spherical in shape and possessed antibacterial property against Staphylococcus aureus and Escherichia coli. Phytochemical screening was performed to identify the chemical constituents present in silver nanoparticles followed by molecular docking studies against penicillin binding proteins found in bacterial strains. In silico designing of silver nanoparticles was done using material science suite followed by probe target interactions. The results displayed a highly stable binding amongst designed nanoparticle and phytochemicals and indicated that the silver nanoparticles possessed antibacterial properties due to phytochemicals present in the extract.

scholarly journals CryoEM structure of the antibacterial target PBP1b at 3.3 Å resolution

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Nathanael A. Caveney ◽  
Sean D. Workman ◽  
Rui Yan ◽  
Claire E. Atkinson ◽  
Zhiheng Yu ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Acid Anhydride ◽  
Atomic Resolution ◽  
Inherent Difficulty ◽  
Penicillin Binding Proteins ◽  
Antibiotic Development ◽  
Class A ◽  
Membrane Mimetic ◽  
Antibacterial Target ◽  
Resolution Structure

AbstractThe pathway for the biosynthesis of the bacterial cell wall is one of the most prolific antibiotic targets, exemplified by the widespread use of β-lactam antibiotics. Despite this, our structural understanding of class A penicillin binding proteins, which perform the last two steps in this pathway, is incomplete due to the inherent difficulty in their crystallization and the complexity of their substrates. Here, we determine the near atomic resolution structure of the 83 kDa class A PBP from Escherichia coli, PBP1b, using cryogenic electron microscopy and a styrene maleic acid anhydride membrane mimetic. PBP1b, in its apo form, is seen to exhibit a distinct conformation in comparison to Moenomycin-bound crystal structures. The work herein paves the way for the use of cryoEM in structure-guided antibiotic development for this notoriously difficult to crystalize class of proteins and their complex substrates.

scholarly journals Enterobactin- and salmochelin-β-lactam conjugates induce cell morphologies consistent with inhibition of penicillin-binding proteins in uropathogenic Escherichia coli CFT073

2021 ◽  
Author(s):  
Artur Sargun ◽  
Timothy C. Johnstone ◽  
Hui Zhi ◽  
Manuela Raffatellu ◽  
Elizabeth M. Nolan
Keyword(s):  
Escherichia Coli ◽  
Binding Proteins ◽  
Uropathogenic Escherichia Coli ◽  
Penicillin Binding Proteins ◽  
E Coli

Siderophore-β-lactam conjugates based on enterobactin and diglucosylated enterobactin enter the periplasm of uropathogenic E. coli CFT073 via the FepA and IroN transporters, and target penicillin-binding proteins.

scholarly journals Function and Localization Dynamics of Bifunctional Penicillin-Binding Proteins in Caulobacter crescentus

2014 ◽  
Vol 196 (8) ◽  
pp. 1627-1639 ◽  
Author(s):  
W. Strobel ◽  
A. Moll ◽  
D. Kiekebusch ◽  
K. E. Klein ◽  
M. Thanbichler
Keyword(s):  
Binding Proteins ◽  
Caulobacter Crescentus ◽  
Penicillin Binding Proteins

scholarly journals Interaction of β-lactam antibiotics with penicillin-binding proteins fromPseudomonas aeruginosa

1982 ◽  
Vol 14 (4) ◽  
pp. 295-298 ◽  
Author(s):  
Alfredo Rodriguez-Tebár ◽  
Fernando Rojo ◽  
Juan C. Montilla ◽  
David Vázquez
Keyword(s):  
Binding Proteins ◽  
Penicillin Binding Proteins

scholarly journals Increasing Ceftriaxone Resistance and Multiple Alterations of Penicillin-Binding Proteins among Penicillin-Resistant Streptococcus pneumoniae Isolates in Taiwan

2007 ◽  
Vol 51 (9) ◽  
pp. 3404-3406 ◽  
Author(s):  
Cheng-Hsun Chiu ◽  
Lin-Hui Su ◽  
Yhu-Chering Huang ◽  
Jui-Chia Lai ◽  
Hsiu-Ling Chen ◽  
...  
Keyword(s):  
Streptococcus Pneumoniae ◽  
Amino Acid ◽  
Binding Proteins ◽  
Binding Protein ◽  
Penicillin Binding Protein ◽  
Penicillin Binding Proteins

ABSTRACT The rate of nonsusceptibility of penicillin-resistant Streptococcus pneumoniae strains to ceftriaxone increased significantly in Taiwan in 2005. Approximately 90% of the ceftriaxone-nonsusceptible isolates were found to be of four major serotypes (serotypes 6B, 14, 19F, and 23F). Seven amino acid alterations in the penicillin-binding protein 2B transpeptidase-encoding region specifically contributed to the resistance.

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