Thiamine → L-Hydroxyproline

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

A plasmid (pHuCol, FIG. 4) encoding the gene sequence of human Type I (α1) collagen (FIGS. 3A and 3B) (SEQ. ID. NO. 1) placed behind the isopropyl-β-D-thiogalactopyranoside (IPTG)-inducible tac promotor and also encoding β-lactamase is transformed into Escherichia coli proline auxotrophic strain NM519 (pro−) by standard heat shock transformation. Transformation cultures are plated on Luria Broth (LB) containing 100 μg/ml ampicillin and after overnight growth a single ampicillin-resistant colony is used to inoculate 5 ml of LB containing 100 μg/ml ampicillin. After growth for 10-16 hours with shaking (225 rpm) at 37° C., this culture is used to inoculate 1 L of M9 minimal medium (M9 salts, 2% glucose, 0.01 mg/mL thiamine, 100 μg/ML ampicillin, supplemented with all amino acids at 20 μg/mL except proline which is supplemented at 12.5 mg/L) in a 1.5 L shaker flask. After growth at 37° C., 225 rpm, for 15-20 hours post-inoculation, the optical density at 600 nm is constant at approximately 0.5 OD/mL. The cells are harvested by centrifugation (5000 rpm, 5 minutes), the media decanted, and the cells resuspended in 1 L of M9 minimal media containing 100 μg/mL ampicillin, 0.08M L-hydroxyproline, and 0.5M NaCl. Following growth for 1 hour at 37° C., 225 rpm, IPTG is added to 1 mM and the cultures allowed to grow for an additional 5-15 hours. Cells are harvested by centrifugation (5000 rpm, 10 minutes) and lysed by mechanical disruption. Hydroxyproline-containing collagen is purified by ammonium sulfate fractionation and column chromatography.

Herkunft & Nachweise