Beta -lipoproteins

The discovery of Lp(a) by Berg in 1962 (B6) relied on the production of rabbit antisera against beta-lipoprotein and on the selective absorption of these antisera with individual human sera. When certain human sera were used for absorption, the antisera retained precipitation capacity in radial immunodiffusion with 30-35% of individual human sera, which obviously contained a previous unknown antigen. The particle carrying the new antigen shared antigenic properties with beta-lipoprotein, but had an additional antigenic structure. This was evidenced from the only partial fusion of the precipitin bands formed between a positive human serum, the antibeta lipoprotein antiserum and the new absorbed antiserum. 

D2. Dahlen, G., Ericson, C., Furberg, C., Lundkvist, L., and Svardsudd, K., Studies on an extrapre-beta lipoprotein fraction. Acta Med. Scand., Suppl. 531, 1-29 (1972). 

K21. Knoblock, E., Hall, C., and Hall, J., Correlation of pre-beta lipoprotein fractions with history... 

M (reduced serum beta-lipoproteins, increased alanine aminotransferase, aspartate... 

The use of surface active agents often modifies the charge of the protein irreversibly through formation of complexes, and because of this a careful study of lipoproteins may prove useful, since anionic detergents influence alpha-lipoproteins, and cationic detergents, beta-lipoproteins (A7, M17). 

L2. Langan, T. A., Durrum, E. L., and Jencks, W. P., Paper electrophoresis as a quantitative method measurement of alpha and beta lipoprotein cholesterol. J. Clin. Invest. 34, 1427 (1955). 

Abetalipoproteinemia is a rare lEM involving lipid dysfunction. Also called Bassen-Komzweig syndrome, it is characterized by extremely low cholesterol due to deficient or absent beta lipoproteins, which are an important component of the cholesterol molecular complex. Symptoms include growth retardation, neurological dysfunction, retinal pigment degeneration, and upper intestinal malabsorption. 

Very low density lipoproteins (VLDL) are synthesized in the liver cell at the contact area of the smooth and rough endoplasmic reticulum and, to a very minor degree, in the mucosa of the small intestine. They have a particle size of 30-80 nm and consist of 90% lipids and 8 — 13% proteins. Their density is <1.006 g/ml. The predominant apohpoproteins are B, C III, and E. They are designated as pre-beta lipoproteins on the basis of their electrophoretic migration. The main function of VLDL is the transport of triglycerides of endogenous origin, (s. fig. 3.8)... 

Sniderman A, Shapiro S, Marpole D, Skinner B, Teng B, ICwiterovich PO, Jr. Association of coronary atherosclerosis with hyperapobetalipoproteinemia [increased protein but normal cholesterol levels in human plasma low density (beta) lipoproteins]. Proc Natl Acad Sci U S A 1980 77 604-8. 

L7. Lawrence, S. H., and Melnick, P. J., Enzymatic activity related to human serum beta-lipoprotein Histochemical, immuno-electrophoretic and quantitative studies. Proc. Soc. ExpU. Biol. Med. 107, 998-1001 (1961). 

The molecular masses of proteins range up to 2,750 kDa for the beta-lipoproteins, and the dynamic ranges for the plasma proteins range from millimoles per liter for albumin to femtomoles for the proteins in lower abundance. The molecular size of the individual protein is an important factor in determining its distribution and transport by the active and passive mechanisms of the body. Some proteins move freely in the extracellular and intravascular spaces, while other intracellular proteins are released only after cell damage. Some of the major plasma proteins are listed in Table 8.1, together with the broad protein fractions designated by their simple electrophoretic mobilities. 

Beta-lipoprotein B eta2-microglobulin Fibrinogen Gamma-globulins Immunoglobulins... 

VLDL—very low density lipoproteins (pre-beta-lipoproteins) ... 

LDL—low density lipoproteins (beta-lipoproteins) and HDL—high density lipoproteins (alpha-l-lipoproteins). 

This method, which was previously commercially available as a kit for measuring cholesterol in beta-lipoproteins, has been discontinued (T2). The following approach was developed by JA Vinson (V2) and modified (K3). 

After 5 min, wash the column again with 2 mL of 0.7% NaCl. Dispose of the washes that contain serum proteins except beta-lipoproteins. 

K2. Kaplan, I. V., Attaelmannan, M., and Levinson, S. S., Fibrinogen is an antioxidant that protects beta-lipoproteins at physiological concentrations in an in vitro cell free system. Atherosclerosis 158, 455 63 (2001). 

A further study (Mechkov et al., 1988) examined the effect of Girosital capsules twice daily for 110 days in 30 patients with cholelithiasis, liver steatosis, and hyperlipoproteinemia. Total cholesterol decreased after 20 days of treatment although it tended to rise slightly later in the test period. The triglycerides were most affected in hyperlipoproteinemia types lib and IV. The beta lipoprotein values were not altered by the treatment. 

The readings for seriun cholesterol, triglyceride, beta d pre-beta lipoprotein levels in the gout patients lay within - 2 standard deviations of the corresponding control mean. This means that they were within the 95 confidence limits for the control population and it is, therefore, unlikely that there is any real difference between gouty and control patients. 

F. R. N. Gurd, and M. Melin Preparation and properties of serum and plasma proteins. XXV. Composition and properties of human serum beta-lipoprotein. J. Amer. chem. Soc. 72, 458—464 (1950). 

Salt, H., H. Wolff, J. Lloyd, A. Fosbrooke, A. Cameron, and D. Hubble On having no beta-lipoprotein. A syndrome comprising a beta-lipoptoteinemia, acanthocytosis, and steatorrhea. Lancet 1960/11, 325—329. 

Heiskell, C. L., R. T. Fisk, W. H. Florsheim, A. Yachi, J. R. Goodman, and C. M. Carpenter A simple method for quantitation of serum beta-lipoproteins by means of immuno-crit. Amer. J. clin. Path. 35, 222 (1961). 

The finding by Barclay et al. (1959) in an affected girl of increased plasma Sf 0—400 lipoproteins and a slightly abnormal distribution of phospholipids among alpha and beta lipoproteins (34 and 61% as compared with the ratio of 46 52 in normal infants) were largely reversible upon controlled intake of a balanced diet. 

With the exception of the occurrence of phytanic acid there are no typical serum findings in HAP. Total serum lipids and total serum cholesterol may be low, but are usually normal. Lipoprotein electrophoresis, performed in a few cases, gave normal results. In contrast to a-beta-lipoproteinemia, with which HAP has many common symptoms, beta-lipoproteins are present. 

Fig. 4. Electrophoretic strip stained for lipid, showing absence of beta-lipoprotein and depletion of a-lipo-protein (Wolff 1965)...

Fig. 5. Serum triglycerides following the ingestion of 30 ml corn oil in normal subjects and in two cases with beta-lipoprotein deficiency. In normal subjects the peak level occurs at 4 hours. In cases 1 and 2 fasting triglycerides were 3 and 6 mg/100 ml serum and no detectable increase occurred for 8 hours (Isselbacher et al. 1964). (With kind permission of Dr. Kurt J.

Blumberg, B. S. Multiple inherited antigenic differences in serum beta-lipoproteins. Clin. Res. 11, 202 (1963). 

M. Lamy, j. Frezal, j. Polonovski et J. Rey L acanthocytose ses rapports avec I absence congenitale de beta-lipoproteines. Presse med. 69, 1546 (1961). 

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