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PubMed1966

Camel myoglobin.

1. Crystalline myoglobin was prepared from camel heart muscle. 2. A method was developed for the isolation of myoglobin that employs molecular-sieve chromatography. 3. Analytical chromatography of the camel myoglobin on a molecular-sieve column and on two types of ion-exchange columns gave in each case a single elution band, which accounted for better than 98% recovery and showed that the product was free from haemoglobin. 4. The iron content on a dry weight basis was 0.308%. This value corresponds to a molecular weight of 18100. 5. The spectra of acidic ferrimyoglobin, basic ferrimyoglobin and ferrimyoglobin cyanide were measured. 6. The pK(a) of the dissociation of the haem-bound water molecule in acidic ferrimyoglobin was 8.53 at 25 degrees . 7. Conclusions are drawn about the charge on the surface of the camel ferrimyoglobin molecule as compared with horse and sperm-whale ferrimyoglobins.

Animals↗

PubMedDate not supplied

Concentration and composition of lipoproteins in blood plasma of the WHHL rabbit. An animal model of human familial hypercholesterolemia.

Lipoproteins in blood plasma have been quantified and characterized in homozygous Watanabe-heritable hyperlipidemic (WHHL) rabbits, an animal model of human familial hypercholesterolemia. Like homozygous human hypercholesterolemics, WHHL rabbits have a severe deficiency of low density lipoprotein (LDL) receptors, a prolonged residence time for LDL, and an increased absolute rate of LDL catabolism. Although lipoproteins containing apolipoprotein B in WHHL rabbits are enriched in cholesteryl esters, their LDL as well as intermediate density lipoproteins (IDL) and very low density lipoproteins (VLDL) also contain a substantial amount of triglycerides and they consistently exhibit hypertriglyceridemia as well as hypercholesterolemia. The cholesteryl esters accumulating in lipoproteins of WHHL rabbits are rich in cholesteryl linoleate and appear to be produced almost exclusively by lecithin-cholesterol acyltransferase. Levels of apolipoprotein B-100 are elevated in VLDL and IDL as well as in LDL of WHHL rabbits and only trace amounts of apolipoprotein B-48 are present. Plasma levels of apolipoprotein E are also substantially increased, and VLDL and IDL are enriched in this protein. The accumulation of lipoproteins with the expected characteristics of remnants of hepatogenous triglyceride-rich lipoproteins contrasts with the efficient hepatic clearance of chylomicron remnants in WHHL rabbits.

Animals↗