Cellular location of enzymes involved in chondroitin sulfate breakdown by Bacteroides thetaiotaomicron.
AUTOR(ES)
Salyers, A A
RESUMO
Bacteroides thetaiotaomicron, a gram-negative anaerobe found in human colons, could utilize chondroitin sulfate, a tissue mucopolysaccharide, as its sole source of carbohydrate. The enzymes responsible for the breakdown of chondroitin sulfate by B. thetaiotaomicron were similar to those produced by Proteus vulgaris and Flavobacterium heparinum and included a lyase (EC 4.2.2.4), which degraded chondroitin sulfate into sulfated disaccharides, sulfatases (EC 3.1.6.4), which removed the sulfate residues, and a glucuronidase, which broke the unsulfated disaccharides into monosaccharide components. Chondroitin sulfate lyase, the first enzyme in the breakdown sequence, was not extracellular. It appeared to be located in the periplasmic space since lyase activity was released by treatment with ethylenediaminetetraacetate and lysozyme. Moreover, sodium polyanethole sulfonate, a high-molecular-weight inhibitor of chondroitin lyase, did not inhibit breakdown of chondroitin sulfate by intact bacteria. The sulfatase and glucuronidase appeared to be intracellular. None of these enzymes was strongly bound to membranes, and none of the steps in the breakdown of chondroitin sulfate was sensitive to oxygen.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=294361Documentos Relacionados
- Location and characteristics of enzymes involved in the breakdown of polygalacturonic acid by Bacteroides thetaiotaomicron.
- Induction of chondroitin sulfate lyase activity in Bacteroides thetaiotaomicron.
- Evidence for differential regulation of genes in the chondroitin sulfate utilization pathway of Bacteroides thetaiotaomicron.
- Use of targeted insertional mutagenesis to determine whether chondroitin lyase II is essential for chondroitin sulfate utilization by Bacteroides thetaiotaomicron.
- Isolation and characterization of two chondroitin lyases from Bacteroides thetaiotaomicron.