Figure 4.
Inhibition of nonsulfated human trypsins by wildtype SPINK1 and variant N34S. Binding of SPINK1 to nonsulfated human cationic (Hu1) and anionic (Hu2) trypsin isoforms (purified from Escherichia coli) was characterized by determining the dissociation constant (KD) values in equilibrium. Measurements were carried out as described in Experimental procedures section. Data from three experiments were fitted globally. The KD values are indicated. Data points represent mean ± SD. Symbol size may be larger than the error bars. SPINK1, serine protease inhibitor Kazal type 1.