Lysosomal proteases in the normal and atherosclerotic arterial wall

Proteolysis of Apoprotein B-100 Impairs Its Topography on LDL Surface and Reduces LDL Association Resistance

“…This violation of LDL particle surface structure destabilizes it, reducing association resistance. Various proteolytic agents are detected in vascular regions damaged by atherosclerosis [5,6], and we therefore hypothesize induction of LDL association in vivo by proteolysis. This hypothesis is confirmed by the fact that fragmented apo B-100 was not once detected in LDL isolated from atherosclerotic areas of arteries [4,8], but never in arteries without visible foci of athero- sclerosis [14].…”

“…Total LDL fraction was isolated by two-step ultracentrifugation in NaBr density gradient [5]. Native LDL were separated from circulating repeatedly modified LDL by lectin chromatography on a column with Ricinus communis agglutinin agarose (Boehringer Mannheim) [12].…”

Aggregation, fusion, and vesicle formation of modified low density lipoprotein particles: molecular mechanisms and effects on matrix interactions

“…Chymase and tryptase, two neutral proteases secreted by mast cells (53), and matrix metalloproteinases secreted by macrophages and smooth muscle cells (54) have been detected extracellularly in the arterial intima. In addition, the arterial intima contains plasma-derived plasmin (55), kallikrein (56,57), thrombin (58), and lysosomal proteases (59,60). Chymase of rat mast cells can extensively hydrolyze the apoB-100 component of LDL particles (61,62) and lysosomal proteases of macrophages degrade apoB-100 at acidic pH (63).…”