Effects of heparin and cholesterol sulfate on the activity and stability of human matrix metalloproteinase 7

Abstract

Sulfated glycosaminoglycans and sulfated lipids are involved in the biological functions of human matrix metalloproteinase 7 (MMP-7). In this study, the effects of heparin and cholesterol sulfate (CS) on the activity and stability of MMP-7 in the hydrolysis of a synthetic substrate, (7-methoxycoumarin-4-yl)were examined. Heparin increased activity by decreasing K m , and the K m values for 0 and 50 μM heparin were 57 ± 8 and 19 ± 5 μM, respectively. CS decreased activity in a non-competitive inhibitory manner with a K i value of 11 ± 3 μM. In thermal incubation at 50−70°C, heparin increased relative activity (the ratio of k cat /K m of MMP-7 with incubation to that without it), while CS decreased relative activity. These results indicate that heparin increases the activity and stability of MMP-7, while CS decreases them.

Effects of salts on the interaction of 8-anilinonaphthalene 1-sulphonate and thermolysin

“…31,32) Briefly, pre-incubation (240 μL) was initiated by mixing 0-50 μL of the ANS solution (2500 μM in buffer A), 0-236 μL of buffer A, and 4 μL of the thermolysin solution (2.0 μM in buffer A) at 25°C for 10 min. The reaction was initiated by adding 10 μL of the substrate solution (0.5 mM) dissolved in DMSO to 240 μL of the pre-incubated solution (total volume 250 μL) at 25°C.…”