Figure 2.
The BnaDGAT1 N-terminal domain partially mediates positive cooperativity. A to C, Substrate saturation curves of full-length BnaDGAT1 (A), BnaDGAT181-501 (B), and BnaDGAT1114-501 (C). The data were fitted with the Hill equation using GraphPad Prism 7.0a. The kinetic parameters are listed in Table I. D, Cross-linking studies of BnaDGAT1 and truncated versions of the enzyme using disuccinimidyl suberate (DSS). The monomeric species is indicated by one asterisk, while the dimer is indicated by two asterisks. The BnaDGAT1 N-terminal region is required for interactions leading to the dimeric enzyme form, which may allow it to partially mediate positive cooperativity through intermolecular interaction. Reported values are means ± sd; n = 3.