   2.8.2.20 | purified TPST1 complexed with two substrate peptides, C4 complement-deived C4P5Y5 or a gastrin peptide, and PAP. PST1-PAP-C4P5Y5 is crystallized by sitting drop vapor diffusion method, mixing of 2.5 mg/ml protein, 2 mM PAP, and 1 mM C4P5Y5 peptide in 50 mM Tris-HCl, pH 7.0, and 200 mM NaCl with reservoir solution consisting of 0.2 M trimethylamine N-oxide dihydrate, 0.1 M Tris-HCl, pH 8.5, and 20% w/v PEG monomethyl ether 2000, nine months, at 20°C. TPST1-PAP-gastrin peptide is crystallized by sitting drop vapor diffusion method, mixing of 5.0 mg/ml protein, 2 mM PAP, and 3 mM gastrin peptide in 50 mM Tris-HCl, pH 7.0, and 200 mM NaCl with reservoir solution consisting of 0.2 M potassium sodium tartrate trihydrate and 19.5% w/v PEG 3350, two months, at 20°C. X-ray diffraction structure determination and analysis at 1.6 A and 2.3 A resolution, respectively. The asymmetric unit of human TPST1-PAP-C4P5Y5 contains two human TPST1 molecules, which assemble to form a dimer. In contrast, the asymmetric unit of TPST1-PAP-gastrin peptide contains four human TPST1 molecules, which assemble to form two dimers |
