FIG. 3.

Incorporation of l-[¹⁴C]lysine by DNT in mammalian cells. EBL cells cultivated for 24 h in medium without l-lysine and for 1 h with l-[¹⁴C]lysine in the absence (A) or presence (B) of 10 μM cycloheximide were treated with partially purified DNT from Bordetella lysates for 1 h and lysed. Proteins were isolated from free l-lysine by filtration through nitrocellulose membranes. Transglutamination was analyzed by measuring the bound radioactivity (shown is the incorporated radioactivity as the mean plus the SD of two independent experiments). The P values between DNT-treated samples and the control were determined by using the Student's t test (∗, P < 0.1; ∗∗, P < 0.01).