Nucleic acids enzymes and

To determine binding constants between drugs and biological structures (e.g., receptors, cells, peptide fragments), proteins (e.g., enzymes), nucleic acids, and plasmids... 

The technique is applicable to a wide range of samples which includes proteins, enzymes, nucleic acids and viruses, and is not limited by the size of the molecules. 

This provisional definition of life... should be sufficient to show that all life has some material structures in common, in the form of enzymes, nucleic acids and... 

Although interferons are mediators of immune response, different mechanisms for the antiviral action of interferon have been proposed. Interferon-a possesses broad-spectrum antiviral activity and acts on virus-infected cells by binding to specific cell surface receptors. It inhibits the transcription and translation of mRNA into viral nuoleic acid and protein. Studies in cell-free systems have shown that the addition of adenosine triphosphate and double-stranded RNA to extracts of interferon-treated cells activates cellular RNA proteins and a oellular endonuclease. This activation causes the formation of translation inhibitory protein, which terminates production of viral enzyme, nucleic acid, and structural proteins (28). Interferon also may act by blocking synthesis of a cleaving enzyme required for viral release. 

Nowadays, very complex molecules can be investigated and the structures of proteins, enzymes, nucleic acids, and even viruses are being revealed by new powerful X-ray diffraction techniques. 

S02/sulphurous acid is most effective in acid media (pH < 4) the activity decreases from SO2 H2SO3 HSOj S03 . At pH 3 only 6% of sulphurous acid is available in its effective undissociated state. The anhydride SO2 is highly reactive and may interact with many constituents of the microbial cell, e.g. SH groups in structural proteins, enzymes, nucleic acids and lipids. Because of its reductive properties SO2 also acts as an antioxidant. 

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