Upper limit to molecular mass of molecules that can freely diffuse through outer membrane of Gram negative bacteria

Value 600 Da
Organism bacteria
Reference Liu Y, Fu X, Shen J, Zhang H, Hong W, Chang Z. Periplasmic proteins of Escherichia coli are highly resistant to aggregation: reappraisal for roles of molecular chaperones in periplasm. Biochem Biophys Res Commun. 2004 Apr 9 316(3):795-801. p. 795 right columnPubMed ID15033470
Primary Source Schirmer T. General and specific porins from bacterial outer membranes. J Struct Biol. 1998 121(2):101-9. AND Koebnik R, Locher KP, Van Gelder P. Structure and function of bacterial outer membrane proteins: barrels in a nutshell. Mol Microbiol. 2000 Jul37(2):239-53.PubMed ID9615433, 10931321
Comments The outer membrane allows free diffusion of molecules smaller than 600 Da due to the presence of non-specific transporters like porins [primary sources]. See Arora et al., 2000 PMID 10636850 p.1594 left column bottom paragraph:"The outer membrane of Gram-negative bacteria serves as a molecular sieve, resisting the entry of noxious compounds, while at the same time allowing the uptake of essential nutrients. Molecules up to about 600 Da in size are taken up by a set of more or less substrate-specific porins and transporters. Outer membrane proteins were among the first integral membrane proteins for which crystal structures have been solved by x-ray diffraction."
Entered by Uri M
ID 105611