In vitro synthesis of cellulose II from a cytoplasmic membrane fraction of Acetobacter xylinum
AUTOR(ES)
Bureau, Thomas E.
RESUMO
The cytoplasmic and outer membranes of Acetobacter xylinum (ATCC 53582) were isolated by discontinuous sucrose density ultracentrifugation. Both lysozyme (EC 3.2.1.17) and trypsin (EC 3.4.21.4) were required for efficient crude membrane separation. Primary dehydrogenases and NADH oxidase were used as cytoplasmic membrane markers, and 2-keto-3-deoxyoctulosonic acid was used to identify the outer membranes. Cellulose synthetase (UDP-glucose:1,4-β-D-glucan 4-β-D-glucosyltransferase; EC 2.4.1.12) activity was assayed as the conversion of radioactivity from UDP-[14C]glucose into an alkali-insoluble β-1,4-D-[14C]glucan. This activity was predominantly found in the cytoplasmic membrane. The cellulose nature of the product was demonstrated by (i) enzymatic hydrolysis followed by TLC, (ii) methylation analysis followed by TLC, and (iii) GC/MS. Further, the weight-average and number-average degree of polymerization of the in vitro product, determined by high-performance gel permeation chromatography, were 4820 and 5270, respectively. In addition, x-ray diffraction analysis indicated that the in vitro product is cellulose II, which is in contrast to the in vivo product—namely, cellulose I.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=299213Documentos Relacionados
- Requirement for a membrane potential for cellulose synthesis in intact cells of Acetobacter xylinum
- SYNTHESIS OF CELLULOSE FROM PYRUVATE BY SUCCINATE-GROWN CELLS OF ACETOBACTER XYLINUM
- Genetic organization of the cellulose synthase operon in Acetobacter xylinum.
- SYNTHESIS OF CELLULOSE BY ACETOBACTER XYLINUM VI. : Growth on Citric Acid-Cycle Intermediates
- Identification of a second cellulose synthase gene (acsAII) in Acetobacter xylinum.