Some Physicochemical Properties of Specific Polysaccharides

Heidelberger, Michael; Kendall, Forrest E.

doi:10.1016/s0021-9258(18)76362-x

Cited by 28 publications

(3 citation statements)

References 16 publications

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“…(2) It possesses a particularly large capsule, the state of which determines its susceptibility to phagocytosis (6,7). (3) Its capsule contains a polysaccharide with unique physicochemical properties (8).…”

Section: Plates 4 Andmentioning

confidence: 99%

The Inhibition of Surface Phagocytosis by the Capsular "Slime Layer" of Pneumococcus Type Iii

Wood¹,

Smith²

1949

Journal of Experimental Medicine

102

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Five strains of type III pneumococcus have been shown to possess wide capsular slime layers during the logarithmic phase of growth in serum broth. The slime layer stains metachromatically with methylene blue and can be visualized under the electron microscope as a fuzzy halo which extends well beyond the surace of the capsule proper and causes centrifugates of the organism to be of extremely large volume. This outer capsular structure is most readily demonstrated in vivo and in nutrient broth containing glucose and serum. It disappears from the surface of the cell with aging of the culture, and is easily removed by dilute alkali, alcohol, and heat. Exposure of slime-covered type III pneumococci to homologous antibody and to type III polysaccharidase reveals that the slime layer contains the same type-specific polysaccharide that is present in the rest of the capsule. From a type III strain producing a prominent slime layer an intermediate mutant has been isolated which forms small non-mucoid colonies on blood agar and possesses a relatively small capsule with a barely discernible slime layer. The wide slime layer protects virulent type III pneumococci from surface phagocytosis. Whenever the type III cells lose their broad slime layer, whether from aging of the culture, from mutation, from exposure to injurious chemicals, or from the action of type III polysaccharidase, they become susceptible to phagocytosis by the surface mechanism. Once phagocyted the type III pneumococci are promptly destroyed, even in the absence of antibodies.

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Section: Plates 4 Andmentioning

confidence: 99%

The Inhibition of Surface Phagocytosis by the Capsular "Slime Layer" of Pneumococcus Type Iii

Wood¹,

Smith²

1949

Journal of Experimental Medicine

102

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show abstract

“…Since antibody probably exists in solution in physiological media as an ionized globulin-sodium chloride complex, and S III is the highly ionized salt of a polyvalent aldobionic acid (12,17), the reactions are probably ionic, and the application of the mass law in some form would seem justified. The precipitin reaction between S III and homologous antibodies would then be merely a more complex instance of a specific precipitation, such as that between barium and sulfate ions.…”

mentioning

confidence: 99%

“…This might be overcome by assuming a continuous series of solid solutions, or that the mutual multivalence of S and A is so great that a continuous series of compounds could result. While there is both structural (12,17) and other (18) evidence that S III contains a number of immunologically reactive groupings, or valences, and while as much as is known of the structure of proteins permits the assumption of recurrent groups of amino acids which might be the centers of specific combination, there are valid objections to these views. Foremost is the finding that the composition of the precipitate depends not upon the antibody concentration at equilibrium (20) (table 2) but on the proportions in which the components are mixed.…”

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confidence: 99%