These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: A protective surface protein from type V group B streptococci shares N-terminal sequence homology with the alpha C protein.
    Author: Lachenauer CS, Madoff LC.
    Journal: Infect Immun; 1996 Oct; 64(10):4255-60. PubMed ID: 8926097.
    Abstract:
    Infection by group B streptococci (GBS) is an important cause of bacterial disease in neonates, pregnant women, and nonpregnant adults. Historically, serotypes Ia, Ib, II, and III have been most prevalent among disease cases; recently, type V strains have emerged as important strains in the United States and elsewhere. In addition to type-specific capsular polysaccharides, many GBS strains possess surface proteins which demonstrate a laddering pattern on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and resistance to trypsin digestion. These include the alpha C protein, the R proteins, and protein Rib. Some of these proteins elicit protective antibodies in animals. We demonstrate a trypsin-resistant laddering protein purified from a type V GBS strain by mutanolysin extraction and column chromatography. This protein contains a major 90-kDa band and a series of smaller bands spaced approximately 10 kDa apart on SDS-PAGE. Cross-reactivity of the type V protein with the alpha C protein and with R1 was demonstrated on Western blot (immunoblot). N-terminal sequence analysis of the protein revealed residue identity with 17 of 18 residues at corresponding positions on the alpha protein. Western blot of SDS extracts of 41 clinical type V isolates with rabbit antiserum to the protein demonstrated a homologous protein in 25 isolates (61%); two additional strains exhibited a heterologous pattern which was also demonstrated with 4G8, a monoclonal antibody directed to the alpha C protein repeat region. Rabbit antiserum raised to the type V protein conferred protection in neonatal mice against a type V strain bearing a homologous protein. These data support the hypothesis that there exists a family of trypsin-resistant, laddering GBS surface proteins which may play a role in immunity to GBS infection.
    [Abstract] [Full Text] [Related] [New Search]