Suitable for the determination of acetoacetate and D(-)-3-hydroxybutyrate by the method of Williamson, D. H., and Mellanby, J., Methods of Enzymatic Analysis, Bergmeyer, H., ed., 2nd edition, 4, 1836 (1974).
Purify the dehydrogenase by two sequential chromatography steps on two triazine dye-Sepharose matrices. [Scavan et al. Biochem J 203 699 1982.] Interferons [IFN]. Interferons are a family of glycosylated proteins and are cytokines which are produced a few hours after cells have been infected with a virus. Interferons protect cells from viral infections and have antiviral activities at very low concentrations (~3 x 10-4M; less than 50 molecules are apparently sufficient to protect a single cell). Double-stranded RNAs are very efficient inducers of IFNs. There are three main types of IFNs. The IFNs are synthesised in lymphocytes, and the IFNs are formed in infected fibroblasts. The and families are fairly similar, consisting of ca 166 to 169 amino acids. Although IFNs are also small glycosylated proteins (ca 146 amino acids), they are different because they are not synthesised after viral infections but are produced by lymphocytes when stimulated by mitogens (agents that induced cell division). Several of these IFNs of mouse and human lymphocytes and fibroblasts are available commercially and have been best prepared in quantity by recombinant DNA procedures because they are produced in very small amounts by the cells. The commercial materials do not generally require further purification for their intended purposes. [Pestkas, Interferons and Interferon standards and general abbreviations, Methods Enzymol, Wiley & Sons, 119 1986, ISBN 012182019X, Lengyel, Biochemistry of interferons and their actions, Ann Rev Biochem 51 251-282 1982, De Maeyer & De Maeyer-Guignard, Interferons in The Cytokine Handbook, 3rd Edn, Thomson et al. Eds, pp. 491-516 1998 Academic Press, San Diego, ISBN 0126896623.] Interleukin (from human source). Purify these using lyophilisation and desalting on a Bio-Rad P-6DC desalting gel, then two steps of HPLC, first with hydroxylapatite, followed by a TSK-125 size exclusion column. [Kock & Luger J Chromatogr 296 293 1984.]
