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Direct observation of gold nanoparticle assemblies with the porin MspA on mica.

ABSTRACT: The octameric porin MspA from Mycobacterium smegmatis is sufficiently stable to form a nonmembrane-supported stand-alone porin on mica surfaces. About 98% of all MspA octamers were found to stand upright on mica, with their periplasmic loop regions bound to the hydrophilic mica surface. Both, small (d = 3.7 nm) and large (d = 17 nm) gold nanoparticles bind to MspA, however, in different positions: small gold nanoparticles bind within the MspA pore, whereas the large gold nanoparticles bind to the upper region of MspA. These experiments demonstrate that gold nanoparticles can be positioned at different, well-defined distances from the underlying surface using the MspA pore as a template. These findings represent a significant step toward the use of electrically insulating stable proteins in combination with metal nanoparticles in nanodevices.

SUBMITTER: Basel MT

PROVIDER: S-EPMC2657223 | biostudies-literature | 2009 Feb

REPOSITORIES: biostudies-literature

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Direct observation of gold nanoparticle assemblies with the porin MspA on mica.

Basel Matthew T MT Dani Raj Kumar RK Kang Myungshim M Pavlenok Mikhail M Chikan Viktor V Smith Paul E PE Niederweis Michael M Bossmann Stefan H SH

ACS nano 20090201 2

The octameric porin MspA from Mycobacterium smegmatis is sufficiently stable to form a nonmembrane-supported stand-alone porin on mica surfaces. About 98% of all MspA octamers were found to stand upright on mica, with their periplasmic loop regions bound to the hydrophilic mica surface. Both, small (d = 3.7 nm) and large (d = 17 nm) gold nanoparticles bind to MspA, however, in different positions: small gold nanoparticles bind within the MspA pore, whereas the large gold nanoparticles bind to th ...[more]

PMID: 19236086

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