Biological channels

Lai R, Kim FI, Garavito R M and Arnsdorf M F 1993 Imaging of reconstituted biological channels at molecular resolution by atomic force microscopy Am. J. Physiol. 265 C851... 

I disagree with Dr. Thomas that there are no known biological channels or carriers. I know of at least one example of a clearly demonstrated channel. This is the acetylcholine activated channel in denervated muscle demonstrated so elegantly by Neher and Sackmann (Nature, 260, 119, 1976), who resolved unit conductance jumps that are far too large to be accounted for by a carrier mechanism. A less unambiguously demonstrated example of channels are the Na+ and K+ channels of nerve, which both by noise analysis and pharmacological evidence imply the movement of about 1000 times as many ions in a unit of time as is reasonable for any diffusive carrier mechanism across the entire membrane. 

After completing a Ph.D. degree and postdoctoral research in analytical chemistry, Saul Goldman joined the University of Guelph in 1972. As a reformed experimentalist, he developed a research program based on statistical mechanics,277 with special interests in supercritical fluid extraction, spectra of endohedral fullerenes,278 the transport of ions through biological channels, and the molecular basis for the properties of liquids and solutions.279... 

More direct biological channels also seem promising as sources. Land plants release H2S, but the process has not been considered for marine algae ( ). Intermittent deep sulfide maxima could be connected with anoxic microenvironments recently located in marine snow. These organic particulates accumulate in the pycnocline and offer potential sites for contrary redox reactions such as dissimilatory sulfate reduction (34). 

While NMR spectroscopy has provided much information about many aspects of channel structure and properties, many questions remain unanswered. With the advent of ultra-high magnetic field strengths and new techniques, such as TROSY, " which permits the NMR analysis of the structure, dynamics and interactions of proteins whose size is in the 100 kDa range and above, the future seems very bright for the application of NMR spectroscopy to the study of ion-transporting biological channels. 

Putney, J. W. 2001. Cell biology channeling calcium. Nature 410 648-649. 

The amount of organic matter in a mineral soil is an extremely important factor in the determination of its characteristics and suitability for use in agriculture. It is a substance that has many desirable properties and essentially no undesirable ones. It exerts its beneficial effects through physical, chemical and biological channels. 

The alternative approach to demonstrations of channel formation in biological membranes is to extract channels from biological materials and then to incorporate these into lipid bilayers where their biological properties can be demonstrated. Little progress has been made so far, probably because biological channels are not easily solubilised and purified, particularly when they are only present in the membrane in small amounts. Furthermore, even when isolated, the native conformation may be irrevocably lost. 

Permeation of Ions Through a Model Biological Channel Effect of Periodic Boundary Conditions and Cell Size. 

The Role of the Dielectric Barrier in Narrow Biological Channels A Novel Composite Approach to Modeling Single-Chaimel Currents. 

In Chapter 4, Marco Saraniti, Dr. Shela Aboud, and Robert Eisenberg introduce the mathematics and biophysics of simulating ion transport through biological channels. Understanding how ion channels work has become a hot... 

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