Isolation and partial characterization of outer and inner membranes from encapsulated Haemophilus influenzae type b.
Loeb, M R
A method has been developed to separate the cell envelope of encapsulated (type b) Haemophilus influenzae into its outer and inner membrane components with procedures that avoided two problems encountered in fractionation of this envelope: (i) the tendency of the outer and inner membranes to hybridize and (ii) the tendency of the apparently fragile inner membrane to fragment into difficulty sedimentable units. Log phage cells, whose lipids were radioactively labeled, were lysed by passage through a French press. The lysate was applied to a discontinuous sucrose gradient, and envelope-rich material was collected by centrifugation onto a cushion of dense sucrose under carefully controlled conditions. This material was then further fractionated by isopycnic centrifugation in a sucrose gradient to yield four membrane fractions which were partially characterized. On the basis of their radioactivity, buoyant density, ultrastructure, polypeptide composition, and content of phospholipid, protein, lipopolysaccharide, and succinic dehydrogenase, these fractions were identified as follows: fraction 1, outer membrane vesicles with very little inner membrane contamination (less than 4%); fraction 2, outer membrane vesicles containing entrapped inner membrane; fraction 3, a protein-rich fraction of inner membrane; fraction 4, a protein-poor fraction of inner membrane. Fractions 3 and 4 contained about 25% outer membrane contamination.
ACESSO AO ARTIGOhttp://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=217309
- Purification and partial characterization of outer membrane proteins P5 and P6 from Haemophilus influenzae type b.
- Isolation of an outer membrane hemin-binding protein of Haemophilus influenzae type b.
- Isolation of the capsular polysaccharide from culture supernatant of Haemophilus influenzae type b.
- Haemophilus influenzae type b.
- Transmembrane permeability channels across the outer membrane of Haemophilus influenzae type b.