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Hannah Johnson

Publications and source records attributed to Hannah Johnson.

3 recordsLinked to original sources
PubMed2006

Carbon nanotube supported single phospholipid bilayer.

Single bilayer membranes of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) were formed on micron thin-films of hydrophilized carbon nanotubes (CNT) by fusion of small unilamellar vesicles. The structure of the membrane was investigated using neutron reflectivity (NR). The underlying thin film of CNT was formed by chemical vapor deposition (CVD) in the presence of Fe catalyst, followed by reaction with 5 M nitric acid to render the film hydrophilic. We demonstrate that this platform lends support to homogeneous and continuous bilayer membranes that have promising applications in the fields of biomaterials, biosensors, and biophysics.

Nanotubes, Carbon↗
PubMed2003

Production and secretion of Aspergillus nidulans catalase B in filamentous fungi driven by the promoter and signal peptide of the Cladosporium fulvum hydrophobin gene hcf-1.

We describe here the use of sequences from the hydrophobin gene hcf-1 of Cladosporium fulvum to construct pCatBex, a vector for high-level expression and secretion of CatB, a catalase from Aspergillus nidulans. Transformation of C. fulvum with pCatBex results in a 60-fold increase in the mycelial activity in the fungus and the appearance of up to 5.4 mkat/l of catalase in the growth medium. The levels of catalase in the supernatant increased dramatically following removal of nitrogen from the medium. Conversely, the overall specific activity of catalase in the cytoplasm did not change appreciably. This indicates that nitrogen depletion induces greater secretion of protein. The vector pCatBex also directs the expression and secretion of CatB in Magnaporthe grisea and may be a useful vector for the expression of genes in other filamentous fungi.

Amino Acid Sequence↗