Scientists have discovered a new pathway for creating biopolymers, according to a paper to be published online this week in Nature Chemical Biology. In contrast to synthetic polymers, biopolymers ? composed of biological building blocks such as amino acids ? can be produced inside cells and are more likely to be biodegradable. This report expands our understanding of biological synthesis and provides a method for creating a wider array of biopolymers.
Epsilon-Polylysine is a natural homopolymer ? a repeated sequence of the same small building blocks of varying length. It is extremely unusual for a biopolymer to be made without a specific sequence ? or, in this case, one preferred length, so the origin of this variability was unknown.
Yoshimitsu Hamano and colleagues show that the different lengths are created by an unusual protein. The biosynthetic enzyme Pls mixes the functions of known enzymes to allow strict control over some parts of the assembly process but variable outcomes in others. The authors further demonstrate that they can take advantage of this enzymatic ‘laziness’ by adding different building blocks to create new polymers, which may prove useful in applications from biodegradable plastics to cellular nanodevices.