biological nanoobjects
(rus. нанообъекты, биологические otherwise наноразмерные биологические объекты)
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components of living systems with linear sizes of 1-100 nm in at least one dimension.
Description
Biological nanoobjects include proteins, nucleic acids (DNA, RNA) and polysaccharides that form the intracellular scaffolding (cytoskeleton) and extracellular matrix, membrane channels, receptors and transporters, intracellular signaling system, machinery for the synthesis, packaging and recycling of proteins and nucleic acids, energy generation, intracellular transport and cell moltility. Dimensions of proteins and supramolecular protein complexes vary from 1 nm to 1000 nm. The diameter of a DNA helix is 2 nm, while it may be as long as several centimetres. Protein complexes that form threads of cytoskeleton are 7 to 25 nm thick and several microns long. Protein complexes that form pores may reach 120 nm in diameter. The size of extracellular structures may also be in the nanoscale. For instance, exosomes, the vesicles that carry cell products between cells, have a diameter of 65-100 nm, while the size of blood plasma lipoprotein particles that transport lipids varies from 8 to 50 nm (see fig.). Viruses are the only nanoscale form of living matter (reference of viruses to the category of life forms is arguable, see virus). Their sizes range from 25 to 300 nm.
Biology and nanotechnology have a wide “interface”. The above facts indicate that biological systems are made up of nanoscale building blocks and molecular machines (motors). Their organisation and operating principles offer a multitude of new approaches and structures for nanotechnology. At the same time, nanotechnology provides biology with tools and techniques for studying the organisation of living matter at the molecular level. On the one hand, commensurability of biological structures and artificial nanomaterials may define the biological and toxicological properties of the latter. On the other hand, biological structures may be used to design new nanoscale devices.
Biology and nanotechnology have a wide “interface”. The above facts indicate that biological systems are made up of nanoscale building blocks and molecular machines (motors). Their organisation and operating principles offer a multitude of new approaches and structures for nanotechnology. At the same time, nanotechnology provides biology with tools and techniques for studying the organisation of living matter at the molecular level. On the one hand, commensurability of biological structures and artificial nanomaterials may define the biological and toxicological properties of the latter. On the other hand, biological structures may be used to design new nanoscale devices.
Illustrations
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Blood plasma lipoproteins are an example of nanoobjects. Chylomicrons — 1 micron, VLDL — very little density lipoproteins — 30–50 nm, IDL — intermediate density lipoproteins— 40 nm, LDL — low-density lipoproteins — 17–25 nm, HDL— high-density lipoproteins— 8–12 nm. |
Authors
- Borisenko Grigory G.
- Shirinsky Vladimir P.