word of the day: spheroplast

The word of the day is spheroplast:

Biol. a bacterium or plant cell bound by its plasma membrane, the cell wall being deficient or lacking and the whole having a spherical form. (OED)


"In the first study aimed at identifying the in vivo substrates of GroEL, E. coli cells were lysed on ice in the presence of EDTA (to prevent ATP-dependent release of substrate) and GroEL-bound substrates were immunoprecipitated, isolated on 2D gels and identified by mass spectrometry.  The results of that work were challenged, however, on the grounds that substrate binding may have occurred not in vivo, but during cell lysis.  This uncertainty was circumvented in a subsequent study by isolating substrate-containing GroEL-GroES complexes from E. coli spheroplasts expressing C-terminally His6-tagged GroES using immobilized metal-affinity chromatography."

 - Ariel Azia, Ron Unger, and Amnon Horovitz, "What distinguishes GroEL substrates from other Escherichia coli proteins?", FEBS Journal 279:543 (2012)