One-Pot Two-Step Metabolic Labeling of Teichoic Acids and Direct Labeling of
Peptidoglycan Reveals Tight Coordination of Both Polymers Inserted
into Pneumococcus Cell Wall
posted on 2018-07-16, 00:00authored byJulie Bonnet, Yung-Sing Wong, Thierry Vernet, Anne Marie Di Guilmi, André Zapun, Claire Durmort
A method
for labeling teichoic acids in the human pathogen Streptococcus
pneumoniae has been developed using a one-pot
two-step metabolic labeling approach. The essential nutriment choline
modified with an azido-group was incorporated and exposed at the cell
surface more rapidly than it reacted with the strain promoted azide
alkyne cycloaddition (SPAAC) partner also present in the medium. Once
at the cell surface on teichoic acids, coupling of the azido group
could then occur within 5 min by the bio-orthogonal click reaction
with a DIBO-linked fluorophore. This fast and easy method allowed
pulse-chase experiments and was combined with another fluorescent
labeling approach to compare the insertion of teichoic acids with
peptidoglycan synthesis with unprecedented temporal resolution. It
has revealed that teichoic acid and peptidoglycan processes are largely
concomitant, but teichoic acid insertion persists later at the division
site.