Using a cellulose-complementary oligosaccharide as a tool to probe exposed cellulosic surfaces in cotton fibres and growing plant cell walls.
Biochem J
; 481(18): 1221-1240, 2024 Sep 18.
Article
en En
| MEDLINE
| ID: mdl-39207824
ABSTRACT
Cellulosic microfibrils in plant cell walls are largely ensheathed and probably tethered by hydrogen-bonded hemicelluloses. Ensheathing may vary developmentally as hemicelluloses are peeled to enable cell expansion. We characterised a simple method to quantify ensheathed versus naked cellulosic surfaces based on the ability to adsorb a radiolabelled 'cellulose-complementary oligosaccharide', [3H]cellopentaitol. Filter-paper (cellulose) adsorbed 40% and >80% of aqueous 5â
nM [3H]cellopentaitol within â¼1 and â¼20â
h respectively. When [3H]cellopentaitol was rapidly dried onto filter-paper, â¼50% of it was desorbable by water, whereas after â¼1 day annealing in aqueous medium the adsorption became too strong to be reversible in water. 'Strongly' adsorbed [3H]cellopentaitol was, however, â¼98% desorbed by 6â
M NaOH, â¼50% by 0.2â
M cellobiose, and â¼30% by 8â
M urea, indicating a role for hydrogen-bonding reinforced by complementarity of shape. Gradual adsorption was promoted by kosmotropes (1.4â
M Na2SO4 or 30% methanol), and inhibited by chaotropes (8â
M urea), supporting a role for hydrogen-bonding. [3H]Cellopentaitol adsorption was strongly competed by non-radioactive cello-oligosaccharides (Cell2-6), the IC50 (half-inhibitory concentration) being highly size-dependent Cell2, â¼70â
mM; Cell3, â¼7â
mM; and Cell4-6, â¼0.05â
mM. Malto-oligosaccharides (400â
mM) had no effect, confirming the role of complementarity. The quantity of adsorbed [3H]cellopentaitol was proportional to mass of cellulose. Of seven cottons tested, wild-type Gossypium arboreum fibres were least capable of adsorbing [3H]cellopentaitol, indicating ensheathment of their microfibrillar surfaces, confirmed by their resistance to cellulase digestion, and potentially attributable to a high glucuronoarabinoxylan content. In conclusion, [3H]cellopentaitol adsorption is a simple, sensitive and quantitative way of titrating 'naked' cellulose surfaces.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Oligosacáridos
/
Pared Celular
/
Celulosa
/
Fibra de Algodón
Idioma:
En
Revista:
Biochem J
Año:
2024
Tipo del documento:
Article