Apolipoprotein molecular weight

Apolipoprotein Molecular weight Lipoprotein association Function (if known)... 

Apolipoprotein Molecular Weight (Da) Chromosomal Location Function Lipoprotein Carrler(s)... 

Apolipoprotein Molecular weight Lipoprotein class Concentration in plasma (mg/dl)... 

Apolipoprotein Molecular weight (Da) Concentration (m dl) Tissue origin Function... 

Lipoprotein (a) is an independent risk factor for coronary artery disease [68]. It consists of two components an LDL particle and apolipoprotein (a) which are linked by a disulfide bridge. Apo(a) reveals a genetically determined size polymorphism, resulting from a variable number of plasminogen kringle IV-type repeats [69]. Statins either do not affect Lp(a) or may even increase Lp(a) [70, 71]. In a study of 51 FH patients, treated with 40 mgd 1 pravastatin, it has been shown that the increase in Lp(a) was greatest in patients with the low molecular-weight apo(a) phenotypes [70]. 

M29. Molgaard, J., Klausen, I. C., Lassvik, C., Faergeman, O., Gerdes, L. U., andOlsson, A. G., Significant association between low-molecular-weight apolipoprotein(a) isoforms and intermittent claudication. Arteroscler. Thromb. 12, 895-901 (1992). 

Lipoproteins have hydrophobic core regions containing cholesteryl esters and triglycerides surrounded by unesterified cholesterol, phospholipids, and apoproteins. Certain lipoproteins contain very high-molecular-weight proteins that exist in two forms B-48, formed in the intestine and found in chylomicrons and their remnants and B-lOO, synthesized in liver and found in VLDL, VLDL remnants(IDL),LDL (formed from VLDL), and Lp(a) lipoproteins. HDL consist of at least 15 discrete molecular species. All species contain apolipoprotein A-I (apoA-I). Fifty-three other proteins are known to be distributed variously among the HDL species. 

Apolipoprotein B is the major protein component of LDL, and it appears to be an essential component of chylomicrons, VLDL, and LDL. Unlike other apolipoproteins, apoB is insoluble in aqueous buffers after delipidation with organic solvents, and it does not exchange between lipoprotein particles. This may be because of its molecular weight and insolubility it is by far the largest of the apolipoproteins, although, as noted in Section 4.4.1, estimates of molecular weight vary. 

Olofsson et al. (05) have described apolipoprotein F from HDL. With a molecular weight of 26,000-32,000, and a pi of 3.7, amino acid analysis of apoF demonstrated all common amino acids except tryptophan. Olofsson et al. (04) have also isolated a glycine- and serine-rich polypeptide from HDL, which appears to be a unique polypeptide of Mr 4900. 

Steele, J. C. H., Jr., and Reynolds, J. A., Molecular weight and hydrodynamic properties of apolipoprotein B in guanidine hydrochloride and sodium dodecyl sulfate solutions. J. Biol. Chem. 254, 1639-1643 (1979). 

Larger molecules such as proteins usually do not fit these predictions, probably because the molecules adopt an ordered three-dimensional structure in which many of the hydrophobic residues are buried within the structure and unavailable for interaction with the reversed phase. As might be expected from the proposed mechanism of separation, the retention of proteins on reversed-phase columns is not related to molecular weight of the sample, but rather the surface polarity of the molecule. Table I shows that there is a correlation of hydrophobicity (measured by mole % of strongly hydrophobic residues) with retention order for seven different proteins. It is unlikely that the retention of all proteins on a reversed-phase column can be correlated in this manner, because many protein structures have few nonpolar residues exposed to the aqueous environment. For example, although the major A and C apolipoproteins are eluted from a ju-Bondapak alkylphenyl column in an order which can be related to the proposed secondary structures, there is little correlation with the content of hydrophobic residues in each protein and the degree of interaction with the stationary phase. A similar lack of correlation be-... 

Molecular weights shown are for human apolipoproteins the weight for apoA-11 is for the dimer. 

Apolipoprotein Plasma Concentration (mg/dL) (approximate) Molecular Weight Major Density Class Biological Function in Addition to Structural and TVansport Role... 

Apolipoprotein Lipoprotein Density Class Approximate Plasma Concentration (mg/dL) Approximate Molecular Weight (kDa) Reported Functions Major Site of Synthesis... 

LDL consist of a lipid core of cholesteryl esters and triglycerides surrounded by a coat of cholesterol and phospholipids. The coat contains several molecules of vitamin E and apolipoprotein. Under oxidant stress, both lipids and protein are oxidized. The breakdown of the PUFA yields aldehydes and ketones of small molecular weight, which go on to react further. These structural changes ensure that oxidized LDL ceases to be a substrate for the LDL receptor instead it becomes a substrate for the scavenger receptor. 

The characterization of the proteins adsorbed, or immobilized, on substrates by TOF-SIMS has contributed to the development of other analytical techniques. In 1986, the isolation of an apolipoprotein was studied with TOF-SIMS [68], and an accurate molecular weight of peptides was obtained. Moreover, it became evident at that time that it was feasible to monitor on a microscale basis for the genetic polymorphisms of proteins, and also for posttranslational modifications, by this method. 

Apolipoproteins of the C group are peptides of small molecular weights, present in chylomicrons, VLDL, IDL, and HDL. These polypeptides have common characteristics they are regulators (activators or inhibitors) of the lipid metabolism of lipoproteins, particularly the catabolism of triglyceride-rich hpoproteins [1]. The distribution of the different Apo C in lipoprotein classes varies between normal subjects and hypertriglyceridemics and in relation to fasting and the type of diet. 

Further metabolism of lipoprotein triglyceride of VLDL is accompanied by the loss of the smaller molecular weight apolipoproteins. Compared to VLDL, the proportions of apoE and apoB in IDL are increased. The most abundant apoprotein is apoC-III (Table 6). The proportion of apoC-I in IDL is increased about 3-fold compared to most VLDL. The metabolism of IDL is too poorly understood to appreciate the significance, if any, associated with its apoprotein composition. 

Apolipoprotein Lipoprotein (Approximate molecular weight (kD)) Source (Average plasma) concentration (mg dL ) (Physiologic) function... 

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