Procaryotic sources

This chapter reviews recent experimental evidence of a bacterial source of sodium channel blockers, principly TTXs. These findings support the hypothesis that procaryotic organisms produce TTXs which contaminate oceanic food chains. 

Various procaryotic microorganisms can produce polyhydroxyalkanoates using regenerable carbon sources. This polymer is a storage material and can make up to 90 % of the dried cell weight. The most widely researched material in this group up till now is the poly-D(-)-3-hydroxybutyric acid (PHB). 

The Cu2Zu2 enzymes can be obtained from many sources. Apart from two exceptionsthey are exclusively found in eucaryotic organisms in nearly all tissues Only the enzymes from higher species have a blocked N-terminal group. These enzymes are generally more stable. Whether this phenomenon can be ascribed to the acetylation or not is still open to discussion. Iron SOD s are exclusively prokaryotic, whereas manganese superoxide dismutases are present in procaryotic cells as well as in mitochrondria and the serum of vertebrates Their relative molecular... 

In protein stmcture-function studies in which molecular biological techniques are used, the protein in question is expressed in either a procaryotic system (e.g., bacteria such as Escherichia, coli) or a eucaryotic system (e.g., yeast such as Pichiapastoris). Using such expression systems allows for rapid production of a protein or enzyme that has been cloned from its original source [e.g., porcine pepsin(ogen) expressed in E. coli]. These systems are, however, not without their problems. In addition, when using... 

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