Streptococcus mutans dextransucrase: phosphoglycerides and the detection of inhibitory antibodies in sera

1) Rabbit and human sera contain high concentrations of phospholipids which can interact with dextransucrase causing enhanced glucan production. 2) Antibody in sera capable of blocking glucan synthesis can be accurately detected by adding excess LPC and dextran to the enzyme prior to incubating with antiserum and assaying with sucrose.