Evolution of PLA Degrading Enzymes

it is assumed that serine hydrolases had evolved from lipases to proteases via some branching such as cuti-nases, PHB depolymerases, and so on. 

Serine proteases such as proteinase K, subtilisin, a-chymotrypsin, and elastase can hydrolyze PLLA endogenously. Their substrate specificities are relatively wide among proteins that are composed of L-amino acid unit and a-amido bonds, and specific as well, for L-lactic acid unit of PLLA (PLLA, PDLA, and PDLLA) that have a-ester bond. Serine proteases hydrolyze PLLA homopolymer faster than copolymers with low such as PDLLA, poly(lactide-co-glycolide). 

Finally, the relationship between aliphatic polyesters having a-, y-, and e-co-ester bonds and aliphatic poly- 

Lipolytic enzymes such as lipase and esterase play an important role in hydrolyzing not only various triglycerides and fatty acid esters but also natural and synthetic aliphatic polyesters with e-, 6-, or y-ester bonds, that is, cutin, suberin, PCL, PBS, poly(butylene adipate) (PBA), and poly(4-hydro-xybutyrate) (y-PHB) in the environment. PHB with 8-ester bond is hydrolyzed by PHB depolymerase. PHB depolymer- 

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