Chelating agents inhibit activity and prevent expression of streptococcal glucan-binding lectins.

AUTOR(ES)

Lü-Lü

RESUMO

Several of the cariogenic mutans streptococci produce cell wall-associated glucan-binding lectins (GBLs). The lectins bind alpha-1,6-linked glucans and have no affinity for other polysaccharides or anomeric linkages. When citrate or lactate was included in the growth medium, expression of the activities of the GBLs of Streptococcus cricetus and S. sobrinus was prevented. Furthermore, chelating agents, including citrate, lactate, EDTA, and acetylacetone, were able to reversibly inhibit glucan-induced aggregation of GBL+ streptococci. In addition, the chelating agents prevented sucrose-dependent streptococcal adhesion to glass surfaces and dispersed preformed adherent masses of the streptococci. Neither citrate nor other chelating agents modified the activities of glucosyltransferases. Expression of the lectin could only be achieved by the addition of manganous ion to the growth medium. Chloramphenicol and other metabolic inhibitors prevented synthesis of GBL in cells obtained from manganese-deficient medium and shifted to manganous ion-sufficient medium. The GBL may be a manganoprotein, the manganese of which may be perturbed, but not removed, by chelating agents. During synthesis of the GBL, manganous ion may be required in order for the protein to achieve an active conformation. Citrate or other chelating agents may have promise as anticaries agents.

Documentos Relacionados

• Glucan-binding factor in saliva.
• Multiple glucan-binding proteins of Streptococcus sobrinus.
• Expression of the glucan-binding lectin of Streptococcus cricetus requires manganous ion.
• Antigenicity and immunogenicity of a synthetic peptide derived from a glucan-binding domain of mutans streptococcal glucosyltransferase.
• Specificity of the glucan-binding lectin of Streptococcus cricetus.