TY - JOUR
T1 - Cellulose Microfibril Formation by Surface-Tethered Cellulose Synthase Enzymes
AU - Basu, Snehasish
AU - Omadjela, Okako
AU - Gaddes, David
AU - Tadigadapa, Srinivas
AU - Zimmer, Jochen
AU - Catchmark, Jeffrey M.
N1 - Publisher Copyright:
© 2016 American Chemical Society.
PY - 2016/2/23
Y1 - 2016/2/23
N2 - Cellulose microfibrils are pseudocrystalline arrays of cellulose chains that are synthesized by cellulose synthases. The enzymes are organized into large membrane-embedded complexes in which each enzyme likely synthesizes and secretes a β-(1-4) glucan. The relationship between the organization of the enzymes in these complexes and cellulose crystallization has not been explored. To better understand this relationship, we used atomic force microscopy to visualize cellulose microfibril formation from nickel-film-immobilized bacterial cellulose synthase enzymes (BcsA-Bs), which in standard solution only form amorphous cellulose from monomeric BcsA-B complexes. Fourier transform infrared spectroscopy and X-ray diffraction techniques show that surface-tethered BcsA-Bs synthesize highly crystalline cellulose II in the presence of UDP-Glc, the allosteric activator cyclic-di-GMP, as well as magnesium. The cellulose II cross section/diameter and the crystal size and crystallinity depend on the surface density of tethered enzymes as well as the overall concentration of substrates. Our results provide the correlation between cellulose microfibril formation and the spatial organization of cellulose synthases.
AB - Cellulose microfibrils are pseudocrystalline arrays of cellulose chains that are synthesized by cellulose synthases. The enzymes are organized into large membrane-embedded complexes in which each enzyme likely synthesizes and secretes a β-(1-4) glucan. The relationship between the organization of the enzymes in these complexes and cellulose crystallization has not been explored. To better understand this relationship, we used atomic force microscopy to visualize cellulose microfibril formation from nickel-film-immobilized bacterial cellulose synthase enzymes (BcsA-Bs), which in standard solution only form amorphous cellulose from monomeric BcsA-B complexes. Fourier transform infrared spectroscopy and X-ray diffraction techniques show that surface-tethered BcsA-Bs synthesize highly crystalline cellulose II in the presence of UDP-Glc, the allosteric activator cyclic-di-GMP, as well as magnesium. The cellulose II cross section/diameter and the crystal size and crystallinity depend on the surface density of tethered enzymes as well as the overall concentration of substrates. Our results provide the correlation between cellulose microfibril formation and the spatial organization of cellulose synthases.
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U2 - 10.1021/acsnano.5b05648
DO - 10.1021/acsnano.5b05648
M3 - Article
C2 - 26799780
AN - SCOPUS:84960153736
SN - 1936-0851
VL - 10
SP - 1896
EP - 1907
JO - ACS nano
JF - ACS nano
IS - 2
ER -