| 1. |
- Almqvist, Nils, et al.
(author)
-
Methods for fabricating and characterizing a new generation of biomimetic materials
- 1999
-
In: Materials science & engineering. C, biomimetic materials, sensors and systems. - 0928-4931 .- 1873-0191. ; 7:1, s. 37-43
-
Journal article (peer-reviewed)abstract
- Bringing together current ideas in the fields of biomineralization and composite laminate materials, we have attempted to fabricate model materials that mimic abalone nacre through the rapid assembly of inorganic tablets, such as talc. Several physical methods were tested to aid the orientation of the talc tablets in fluid suspensions with a low percentage, 10% by dry weight, of organic binding material. The orientation of talc tablets in the synthesized composites was characterized by X-ray diffraction and scanning electron microscopy. The modulus of rupture of the materials was measured in a three-point bending test. We demonstrate that the alignment of tablets increases by the use of physical methods and from chemical surface treatment. Important factors to consider in making materials that mimic abalone nacre are discussed. Important factors to consider in making materials that mimic abalone nacre are discussed.
|
|
| 2. |
|
|
| 3. |
- Thomson, Neil H., et al.
(author)
-
Oriented, active Escherichia coli RNA polymerase : an atomic force microscope study
- 1999
-
In: Biophysical Journal. - 0006-3495 .- 1542-0086. ; 76:2, s. 1024-1033
-
Journal article (peer-reviewed)abstract
- RNA polymerase (RNAP) molecules to be imaged under aqueous buffer using tapping-mode atomic force microscopy (AFM). Recombinant RNAP molecules containing histidine tags (hisRNAP) on the C-terminus were specifically immobilized on ultraflat gold via a mixed monolayer of two different Ω-functionalized alkanethiols. One alkanethiol was terminated in an ethylene-glycol (EG) group, which resists protein adsorption, and the other was terminated in an N-nitrilotriacetic acid (NTA) group, which binds the histidine tag through two coordination sites with a nickel ion. AFM images showed that these two alkanethiols phase-segregate. Specific binding of the hisRNAP molecules was followed in situ by injecting proteins directly into the AFM fluid cell. The activity of the hisRNAP bound to the NTA groups was confirmed with a 42-base circular single-stranded DNA template (rolling circle), which the RNAP uses to produce huge RNA transcripts. These transcripts were imaged in air after the samples were rinsed and dried, since RNA also has low affinity for the EG-thiol and cannot be imaged under the buffers we used.
|
|
