A Challenge for in-situ observations of chemical reaction and reaction-induced self-assembly; SANS studies of in-vitro synthesis of cellulose via enzymatic polymerization

Hashimoto, Takeji; Tanaka, Hirokazu; Koizumi, Satoshi; Kurosaki, Kazuhiro*; Omae, Masashi*; Kobayashi, Shiro*

We have investigated self-assembling process of cellulose artificially synthesized via enzymatic polymerization by means of in-situ and time-resolved SANS (Small-angle Neutron Scattering). The results elucidated the followings: (1) Cellulose molecules synthesized at a special reaction site of the enzyme (cellulase) located on or near the smooth surface of self-assembled enzymes formed in the reaction medium; (2) The synthesized molecules associated themselves via DLA (diffusion-limited association) and crystallized into fibrils; (3) The fibrils formed the aggregates, which had surface fractal dimension Ds increasing from 2 to 2.3 with the reaction time, on the smooth surface of the enzyme aggregates.