Localization of sugar-binding sites in Staphylococcus aureus using gold-labeled neoglycoprotein.
We studied post- and pre-embedding staining of sugar-binding sites on thin sections of Staphylococcus aureus with an electron microscopic neoglycoprotein-gold technique. Although gold particles of cellobiosyl bovine serum albumin (BSA)-glycosylated BSA-, lactosyl BSA-, and melibiosyl BSA-gold did not label, heavy labeling of N-acetylglucosaminide-BSA-gold was observed in both the cell wall and the cytoplasm on Spurr-embedded thin sections of S. aureus. Inhibition of labeling with wheat germ agglutinin-biotin and N-acetylglucosaminidase indicated that the labeling was due to N-acetylglucosamine. These data suggested that molecules that bind specifically with N-acetylglucosamine occur in the cell wall and cytoplasm of S. aureus. Pre-embedding staining revealed that these molecules are abundant at the surface of the cell wall and that the abundance differs depending on the bacterial strain. An N-acetylglucosamine-specific lectin-like substance, glucosaminidase, and toxins are proposed as candidates for molecules responsible for the labeling, and the possible functional significance of the findings is discussed briefly.
Morioka
H
H
Laboratory of Electron Microscopy, Kyoto Prefectural University of Medicine, Japan.
Suganuma
A
A
Tachibana
M
M
D001665:Binding Sites; D050260:Carbohydrate Metabolism; D006023:Glycoproteins / Q000378:metabolism*; D017979:Gold Colloid; D006651:Histocytochemistry; D008854:Microscopy, Electron; D012710:Serum Albumin, Bovine; D013211:Staphylococcus aureus / Q000378:metabolism* / Q000648:ultrastructure
D006023:Glycoproteins; D017979:Gold Colloid; D012710:Serum Albumin, Bovine