Description
Human Apolipoprotein E (Apo E) |P16
Concentration: | 0.9 mg / ml, determined by the Lowry method |
Source: | From fresh human plasma that has tested negative for Hepatitis C, HIV-I and HIV-II antibodies as well as Hepatitis surface antigens. |
Purification: | After series ultracentrifugations, Very Low density Lipoprotein (VLDL) is isolated from human plasma. Apo E is purified from delipidated VLDL, followed by gel-filtration. Minor impurities of other apo-proteins are then removed by antibody-Sepharose™ affinity column. |
Purity: | ≥ 98% by SDS-PAGE |
Buffer: | 20 mM Tris-HCl, 0.15 mM NaCl, 0.5 mM EDTA, 0.02 % NaN3, pH 7.4. |
Storage: | -20°C for long-term storage, 4°C for short- term storage. Aliquot to avoid repeated freezing and thawing. |
*These products are for research or manufacturing use only, not for use in human therapeutic or diagnostic applications.
IMPORTANCE
Apo E contains 299 amino acid residues. It is a 34-37 kDa glycosylated protein (Rall et al., 1983).
Apo E is involved with triglyceride, phospholipid, cholesteryl ester, and cholesterol transport in and out of cells and is a ligand for LDL receptors. Apo E has also been implicated in immune and nerve degeneration. It has been found to suppress lymphocyte proliferation. Late-onset familial and sporadic Alzheimer disease patients have been found to have a higher occurrence of one of the three common Apo E isoforms, Apo E4. The Apo E4 isoform has been detected in senile plaques and neurofibrillary tangles of Alzheimer disease patients. Apo E4 is associated with rapid chylomicron-remnant clearance and increased total cholesterol levels.