Figure 1. Degradation of MBP by proteolytic activities present in astrocyte lysates.

Lysates from LPS-activated astrocytes were incubated with exogenous MBP, then subjected to SDS-PAGE as described in text. As controls, MBP was incubated without cell lysate (MBP control) or with lysate from unactivated astrocytes (CTRL). A, Calcium dependency of MBP degradation. B, Substrate specificity of proteolytic activity present in LPS-activated lysates towards MBP. C, Dose-dependent degradation of MBP by LPS-activated lysates from astrocytes after incubation at 37°C for 24 h. D, Time-course of the MBP degradation by 30 μl of LPS-activated lysate. In the lower part of C and D MBP degradation is expressed as optical density (OD × mm²) as calculated by densitometrical analysis of gel.