Clinical, biochemical and histological analysis of seven patients with cholesteryl ester storage disease.

Lysosomal acid lipase (LAL) deficiency leads to two phenotypically different diseases: cholesteryl ester storage disease (CESD) and Wolman's disease. Lysosomal acid lipase hydrolyzes cholesteryl esters and triglycerides. Deficiency of LAL results in intralysosomal storage of cholesteryl esters and triglycerides. CESD has a chronic and benign course and is characterized by hepatomegaly and mild hypercholesterolemia. It leads to fibrosis (cirrhosis) and early atherosclerosis. This report presents the clinical, biochemical and microscopic data of seven patients with CESD followed up over 10 years. The physical development of all the study children remained within the normal range; 7 patients had hepatomegaly and 6 also had splenomegaly. Three patients had normal cholesterol, triglycerides and transaminases values; the other four had slightly elevated levels for these parameters. The activity of LAL in all patients was reduced to below 30% of the lower normal value. Histologically, cholesteryl crystals and lipid storage vacuoles in Kupffer cells were present in all examined patients except one. Accumulation of cholesteryl esters was visible on thin-layer chromatography of lipid extracts obtained from liver biopsies.

[Thin-layer chromatography of urine oligosaccharides in diagnosis of some lysosomal storage disorders]. / Chromatografia cienkowarstwowa oligosacharydów moczu w diagnostyce niektórych chorób lizosomalnych.

Inherited lysosomal storage disorders are caused by the deficiency or importantly lowered activity of one of the lysosomal enzymes, leading to the storage in the lysosomes the not degraded high-molecular substrates, among others: mucopolysaccharides, glycolipids, oligosaccharides and glycoproteins. Thin-layer chromatography of urine oligosaccharides allows reliable and fast diagnosis of some lysosomal storage disorders e.g. alpha-mannosidosis, fucosidosis, sialidosis, galactosialidosis, Schindler disease, GM1-gangliosidosis, GM2-gangliosidosis (Sandhoff type), Pompe disease, Salla disease, mucolipidosis II and III. We are presenting a modification of the Humbel and Collart's method of TLC of urine oligosaccharides. The principle of our modification is to introduce of the preliminary desalting step of the urine on the columns containing anionit BioRad AG 1 x 8 and cationit Dowex 50 x 8-200.

Lipidoses detected in Poland through 1993.

It is estimated that 70-100 children suffering from a lysosomal storage disease are born in Poland every year. From 1975 to 1993, the activity of various lysosomal enzymes was determined in the leukocytes, cultured skin fibroblasts, or hair roots from 5,594 patients, mainly children, in whom the diagnosis of a lipidosis was suspected. In that material 162 cases of a lipidosis were diagnosed. Metachromatic leukodystrophy seems to be the most frequent of the lipidoses; GM1 gangliosidosis is more frequent than GM2 gangliosidosis and Gaucher and Niemann-Pick diseases appear to be almost as frequent as the former.

Compartmentation of the amino acid pool in Saccharomycopsis lipolytica.

1. The size of the free amino acid pool in S. lipolytica varies from 250 to 350 micronmoles/g dry wt., and it accounts for about 10% of the total amino acid content; 80-90% of free amino acids, including methionine, is compartmentized in vacuole. S-Adenosylmethionine (SAM) occurs in equal proportions in vacuole and cytoplasm while aspartate and glutamate are mainly cytosolic. 2. The bulk of the methionine overproduced in the ethionine-resistant mutant Etr-13, and of the exogenous methionine derived from the methionine-enriched medium, is stored in vacuole. The amount and distribution of SAM is not affected. 3. Overloading with endogenous methionine results in a significant increase in the total cytosolic amino acid pool and is associated with the increased concentration of arginine, glutamine and lysin; on overloading with exogenous methionine, only lysine is elevated.

Methionine overproduction by Saccharomycopsis lipolytica.

Six ethionine-resistant (Etr) regulatory mutants of Saccharomycopsis lipolytica Sl/1 overproducing methionine have been isolated. Five of them are also resistant to seleno-methionine. The activity of homocysteine synthase (O-acetyl-L-hormoserine-acetate lyase, adding hydrogen sulfide) is derepressed in these mutants and is not susceptible to the methionine-mediated repression. The pool of free methionine in Etr mutants is enhanced 1.5 to 18 times, and incorporation of 35S into methionine is 1.5 to 50 times higher than that in the wild strain. Neither accumulation of endogenous free methionine in Etr mutants nor the uptake of exogenous methionine is accompanied by an increase in the S-adenosylmethionine pool. This implies compartmentation of methionine metabolism in S. lipolytica.

Limiting reactions in activation of acyl units in biosynthesis of macrolide antibiotics.

Formation of propionyl phosphate in Streptomyces erythreus synthesizing a polypropionate erythronolide ring of erythromycin was found to be catalyzed by a specific propionate kinase. The isolated and 100-fold purified kinase was devoid of activity towards acetate and other monocarboxylic acids. The selection for higher antibiotic-synthesizing ability was associated with higher kinase activity and lower K(m) values towards propionate. This relation did not apply to the mutants of S. noursei var. polifungini producing polyene tetraene antibiotics of the nystatin type, composed of acetate and propionate units. Instead, the antibiotic-synthesizing ability was correlated with the activity of acetyl- and propionyl-coenzyme A carboxylase, responsible for the formation of malonyl- and methyl-malonyl-coenzyme A intermediates in the polymerization process.