title: [beta]-Glucan Synthesis in the Cotton Fiber (IV. In Vitro Assembly of the Cellulose I Allomorph).
abstract: In vitro assembly of cellulose from plasma membrane extracts of the cotton (Gossypium hirsutum) fiber was enriched by a combination of 3-(N-morpholino)propanesulfonic acid extraction buffer and two independent digitonin solubilization steps consisting of 0.05% digitonin (SE1) followed by 1% digitonin (SE2). Glucan synthase activity assays revealed that, although the SE2 fraction possessed higher activity, only 8.6% of the in vitro product survived acetic/nitric acid treatment. On the other hand, the SE1 fraction was less active, but 32.1% of the total glucan in vitro product was resistant to acetic/nitric acid. In vitro products synthesized from the SE1 fraction contained [beta]-1,3-glucan and fibrillar cellulose I, whereas the SE2 fraction produced [beta]-1,3-glucan and cellulose II. Both celluloses assembled in vitro were labeled with cellobiohydrolase I-gold complex, and the electron diffraction patterns of both products from SE1 and SE2 revealed cellulose I and cellulose II, respectively. Contamination of native cellulose was ruled out by extensive evidence from autoradiography of the ethanol-insoluble and acetic/nitric acid-insoluble materials, including three different controls.
authors.affiliation: Department of Botany, The University of Texas at Austin, Austin, Texas 78713-7640.
authors.forename: K.
authors.initials: K
authors.lastname: Kudlicka
authors.forename: R. M.
authors.initials: RM
authors.lastname: Brown
authors.forename: L.
authors.initials: L
authors.lastname: Li
authors.forename: J. H.
authors.initials: JH
authors.lastname: Lee
authors.forename: H.
authors.initials: H
authors.lastname: Shin
authors.forename: S.
authors.initials: S
authors.lastname: Kuga