Figure 5.

Guanylyl cyclase activity of the sGCβ1(1–619) proteins in cell supernatants in response to an sGC activator drug or to an NO donor. COS-7 cells were cultured in normal medium (normal) or cultured in heme-depleted conditions (heme def) and transfected to express each sGCβ1(1–619) protein alone or along with sGCα. Their supernatants were collected and used for GTP cyclase activity measurements in response to BAY 58 or to the NO donor NOC-18, as indicated. A, activities of the singly transfected sGCβ1(1–619) proteins; B, activity of the sGCβ1(1–619) proteins when co-transfected with sGCα. Values are the mean ± S.D. (error bars) of three measurements and are representative of two experiments each. The activity of each sGC mutant is compared with WT for significance determination. **, p < 0.01; *, 0.01 < p < 0.05.