Phosphorylase, enzymatic hydrolysis

Oligo- and polysaccharides are degraded in organisms by specific enzymatic hydrolysis (by hydrola ) or phosphorolysis (by phosphorylases). 

Figure 10.3 Enzymatic synthesis of poly(adenylic acid) in self-reproducing oleate liposomes (redrawn from Walde et al., 1994a). (a) The ADP penetrates (sluggishly) the liposome bilayer, (b) in the presence of polynucleotide phosphorylase, ADP is converted in poly(A), which remains entrapped in the liposome, (c) Polycondensation of ADP goes on simultaneously with the self-reproduction of liposomes (A is the membrane precursor, oleic anhydride, which, once added, induces the self-reproduction of liposomes S, surfactant, in this case oleate, which is the hydrolysis product of A on the bilayer E is polynucleotide phosphorylase).

Growing membrane systems have been used to obtain artificial infrabiological systems. Walde et al. [47] have carried out the synthesis of polyadenylic acid in self-reproducing vesicles [48], in which the enzyme polynucleotide phosphorylase carried out the synthesis of poly-A, and membrane vesicle multiplication was due to the hydrolysis of externally provided oleic anhydride to oleic acid. The snag is that the enzyme component is not auto-catalytic. Enzymatic RNA replication in vesicles [49] suffers from the same problem. It is also not known whether redistribution of the entrapped enzymes into newly formed vesicles occurs or not. An affirmative answer would be evidence for vesicle reproduction by fission. 

Bacterial ADP-ribosylating toxins and non-enzymatic NAD hydrolysis 291 Nucleoside and AMP hydrolases 294 Phosphorylase and pyrophosphorylase reactions 297 DNA and RNA 301 Conclusions and future directions 306 The immediate future 306 Crucial questions 307 Acknowledgments 308 References 308... 

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