The availability of a species-specific monoclonal antibody that recognizes the low density lipoprotein (LDL) receptor of human but not hamster origin permitted assignment of the structural gene for the human receptor to chromosome 19. The antibody was used to detect the human LDL receptor in a series of hamster-human somatic cell hybrids by two assays: (i) a structural assay that measured cellu...

Improved techniques of cell isolation resulted in 90 to 100 million monocytes from a single donor. Addition of low density lipoprotein (LDL) to to cultures of these cells resulted in the down regulation of LDL receptor activity. Addition of malondialdehyde-altered LDL. which enters the cell through a receptor for negatively charged proteins (the scavenger receptor), produced an even greater do...

At the present time the most useful technique with which to examine the kinetics of low-density lipoprotein (LDL) cholesterol in vivo is the labeled LDL turnover study. However, a major limitation of this method is that, despite its ability to accurately measure both the plasma LDL concentration and LDL production rate, it cannot directly quantify LDL receptor activity. The present study define...

In the present report we describe a patient with multiple myeloma and long-standing paraproteinemia who developed xanthoma in the absence of an elevation in plasma cholesterol or triglyceride concentrations. Studies demonstrated that our patient's monoclonal IgG antibody interacted with apoprotein B-100. The LDL-antibody complex isolated from our patient did not affect the degradation of LDL by...

1022 L ow-density lipoproteins (LDLs) are a proven causal risk factor for the development of atherosclerotic cardiovascu-lar disease. Plasma levels of LDL cholesterol (LDL-C) and its major protein, apolipoprotein B (apoB), are positively associated with incident cardiovascular events. 1 Individuals with genetic conditions of extremely high LDL-C develop premature cardiovascular disease; convers...

We have studied function and structure of the low density lipoprotein (LDL) receptors in a monensin-resistant (Monr-31) mutant isolated from Chinese hamster ovary (CHO) cells. To assay the ability of the receptor to bind LDL, we employed three methods, 125I-LDL binding to the cells at 4 degrees C, 125I-LDL binding to the receptor-phospholipid complex (Schneider, W.J., Goldstein, J.L., and Brown...

Diffusion of the complex consisting of low density lipoprotein (LDL) bound to its receptor on the surface of human fibroblasts has been measured with the help of an intensely fluorescent, biologically active LDL derivative, dioctadecylindocarbocyanine LDL (dil(3)-LDL). Fluorescence photobleaching recovering and direct video observations of the Brownian motion of individual LDL-receptor complexe...

Incubation of mouse peritoneal macrophages with native human low density lipoprotein (LDL) did not cause any significant storage of intracellular cholesteryl esters. However, when the LDL was subjected to brief (30-second) vortexing, it formed self-aggregates that were rapidly ingested and degraded by macrophages, converting them to cholesteryl ester-rich foam cells. Such aggregates were as pot...

Versican-like proteoglycans are the main component of the intimal extracellular matrix interacting with low density lipoprotein (LDL). The aim of this study has been to investigate the receptors involved in versican-modified LDL uptake by human vascular smooth muscle cells (VSMCs). We have found that versican-LDL interaction leads to the following: (1) monomeric LDL particles that are similar i...