Studies on the Teichoic Acids of the Pneumococcus

Eve Ida Barak Briles

OAI: oai:digitalcommons.rockefeller.edu:student_theses_and_dissertations-1499

The investigations described in this dissertation are presented in two parts. Part I deals with the mode of segregation of the pneumococcal wall teichoic acid during cell growth and division. Teichoic acid was labeled with 3H-choline (a teichoic acid-specific constituent of pneumococci) or an analogue, and its distribution among progeny cells over several generations was followed by autoradiography. The results confirm the zonal growth model for Gram-positive coccal cells. In Part II, the pneumococcal Forssman antigen is identified as a membrane lipoteichoic acid. The following lines of evidence suggest that the teichoic acid chains of the molecule may be identical to those found in the cell wall: (1) they are both composed of the same chemical constituents, including choline; (2) they are both cleaved by periodate and by nitrous acid into choline-containing fragments of similar size; (3) previous investigators demonstrated serological cross-reactivity between the two (Goebel, W. and Adams, M.R., 1943, J. Exp. Med. 77:435-449). Membrane localization of the F-antigen is suggested by the following observations: (1) the F-antigen is accessible from the surface of whole pneumococci; (2) it is not solubilized by muralytic enzymes; (3) it contains lipophilic regions, and is associated with a particulate cell fraction by hydrophobic interactions. The possibility that the lipoteichoic acid may be a precursor to the wall teichoic acid is ruled out by pulse-chase studies.

Life Sciences