title: Gas vesicles are strengthened by the outer-surface protein, GvpC.
abstract: The critical collapse pressure of gas vesicles isolated from Anabaena flos-aquae decreased from 0.557 to 0.190 MPa when GvpC, the hydrophilic 22 kDa protein present on the outer surface of the gas vesicle, was removed by rising in 6 M urea. Recombinant GvpC was purified from inclusion bodies, produced in an E. coli strain containing an expression vector bearing the gene encoding GvpC from A. flos-aquae, and then solubilised in 6 M urea. This recombinant GvpC became bound to gas vesicles that had been stripped of their native protein, when the urea was removed by dialysis; the amount which bound increased with the concentration of GvpC present. The critical pressure of these reconstituted gas vesicles increased to 0.533 MPa, 96% of the original value. These results indicate that the function of GvpC is to increase the strength of the structure.
authors.affiliation: Department of Botany, University of Bristol, UK.
authors.forename: P K
authors.initials: PK
authors.lastname: Hayes
authors.forename: B
authors.initials: B
authors.lastname: Buchholz
authors.forename: A E
authors.initials: AE
authors.lastname: Walsby
mesh_terms: D017033:Anabaena / Q000235:genetics* / Q000378:metabolism; D001426:Bacterial Proteins; D002457:Cell Extracts; D003001:Cloning, Molecular; D005740:Gases / Q000378:metabolism; D006874:Hydrostatic Pressure; D008565:Membrane Proteins / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000235:genetics* / Q000378:metabolism; D011994:Recombinant Proteins; D014508:Urea; D014617:Vacuoles / Q000737:chemistry*
chemical_list: D001426:Bacterial Proteins; D002457:Cell Extracts; D005740:Gases; C076193:GvpC protein, Anabaena flos-aquae; D008565:Membrane Proteins; D010940:Plant Proteins; D011994:Recombinant Proteins; D014508:Urea