Upper limit to molecular weight of molecule that diffuses freely through MscL [Large-conductance mechanosensitive channel] and MscS [Small-conductance mechanosensitive channel]

Range ~1,000 Da
Organism bacteria
Reference Martinac B, Saimi Y, Kung C. Ion channels in microbes. Physiol Rev. 2008 Oct88(4):1449-90. doi: 10.1152/physrev.00005.2008. p.1452 right column top paragraphPubMed ID18923187
Primary Source [166] Kloda A et al., Mechanosensitive channel of large conductance. Intern J Biochem Cell Biol. 2008 40 :164–169.PubMed ID17350877
Comments P.1452 left column bottom paragraph:"Although they conduct ions and are usually characterized by their ionic conductance and selectivity prokaryotic MS ion channels are often referred to as MS channels rather than MS ion channels. This is because in bacteria (and possibly also in Archaea) they primarily serve to transport cellular osmoprotectants other than ions by acting as osmosensors that regulate the cellular turgor (Section II.C). Bacterial MscL and MscS channels have large conductances of ~3 nS and ~1 nS respectively, and lack ionic specificity by passing anything smaller than ~1,000 m.w. including proline, potassium glutamate, trehalose, and ATP (primary source 166). MscL is non-selective for both anions and cations (refs 62, 368) whereas MscS exhibits a slight preference for anions over cations with a permeability ratio PCl : PK = 1.5–3.0:1 (refs 238, 354, 364, 368)." Note-HTML version of article gives primary source [166] (above) whereas pdf version of article gives primary source [117]-Hamill OP, Martinac B. Molecular basis of mechanotransduction in living cells. Physiol Rev. 2001 81: 685–740. PMID 11274342
Entered by Uri M
ID 112279