@article {2624,
	title = {Chemically Induced Cell Wall Stapling in Bacteria.},
	journal = {Cell Chem Biol},
	volume = {28},
	year = {2021},
	month = {2021 Feb 18},
	pages = {213-220.e4},
	abstract = {<p>Transpeptidation reinforces the structure of cell-wall peptidoglycan, an extracellular heteropolymer that protects bacteria from osmotic lysis. The clinical success of transpeptidase-inhibiting \&beta;-lactam antibiotics illustrates the essentiality of these cross-linkages for cell-wall integrity, but the presence of multiple, seemingly redundant transpeptidases in many species makes it challenging to determine cross-link function. Here, we present a technique to link peptide strands by chemical rather than enzymatic reaction. We employ biocompatible click chemistry to induce triazole formation between azido- and alkynyl-d-alanine residues that are metabolically installed in the peptidoglycan of Gram-positive or Gram-negative bacteria. Synthetic triazole cross-links can be visualized using azidocoumarin-d-alanine, an amino acid derivative that undergoes fluorescent enhancement upon reaction with terminal alkynes. Cell-wall stapling protects Escherichia coli from treatment with the broad-spectrum \&beta;-lactams ampicillin and carbenicillin. Chemical control of cell-wall structure in live bacteria can provide functional insights that are orthogonal to those obtained by genetics.</p>
},
	issn = {2451-9448},
	doi = {10.1016/j.chembiol.2020.11.006},
	author = {Rivera, Sylvia L and Espaillat, Akbar and Aditham, Arjun K and Shieh, Peyton and Muriel-Mundo, Chris and Kim, Justin and Cava, Felipe and Siegrist, M Sloan}
}
@article {1442,
	title = {Imaging bacterial peptidoglycan with near-infrared fluorogenic azide probes.},
	journal = {Proc Natl Acad Sci U S A},
	volume = {111},
	year = {2014},
	month = {2014 Apr 15},
	pages = {5456-61},
	abstract = {<p>Fluorescent probes designed for activation by bioorthogonal chemistry have enabled the visualization of biomolecules in living systems. Such activatable probes with near-infrared (NIR) emission would be ideal for in vivo imaging but have proven difficult to engineer. We present the development of NIR fluorogenic azide probes based on the Si-rhodamine scaffold that undergo a fluorescence enhancement of up to 48-fold upon reaction with terminal or strained alkynes. We used the probes for mammalian cell surface imaging and, in conjunction with a new class of cyclooctyne D-amino acids, for visualization of bacterial peptidoglycan without the need to wash away unreacted probe.</p>},
	keywords = {Azides, Fluorescent Dyes, Molecular Imaging, Molecular Probe Techniques, Molecular Structure, Peptidoglycan},
	issn = {1091-6490},
	doi = {10.1073/pnas.1322727111},
	author = {Shieh, Peyton and Siegrist, M Sloan and Cullen, Andrew J and Bertozzi, Carolyn R}
}
