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PubMed1978

Coronary intimal sclerosis in Morquio's syndrome.

Mitral valve, coronary arteries, cartilage, and liver were studied by light and electron microscopy in a 15 year old boy with Morquio's syndrome, a genetic mucopolysaccharidosis, in which a deficiency of lysosomal hexosamine sulfatase is associated with accumulations of keratan sulfate in various organs. Coronary artery intimal sclerosis was a prominent feature of this disorder. Ultrastructural examination revealed numerous intimal smooth muscle cells containing storage vacuoles consistent with lysosomes. This was associated with marked interstitial deposition of collagen, elastin, and basement membrane material. Recent studies of human and experimental atherosclerosis have demonstrated the accumulation of cholesterol within vascular smooth muscle cell lysosomes. Intralysosomal accumulation of substrates other than cholesterol is also associated with vascular intimal sclerosis in genetic lysosomal disorders such as Fabry's disease and Hurler's syndrome. Lysosomal storage of undegraded substrate may be an important pathogenetic mechanism in the development of sclerotic vascular lesions.

Adolescent↗
PubMed1979

Biochemical and serological characteristics of soluble yeast phase antigens of Histoplasma capsulatum.

Soluble antigens of whole yeast-phase cells were extracted with a 0.1 M phosphate buffer containing 0.1 M sodium chloride and 0.02% iodacetate. After being separated by differential filtration into fractions less than or greater than 50,000 daltons these antigens were purified by molecular sieve and chromatographic separations on ionic exchange resins. Two high molecular weight fractions obtained from diethylaminoethyl-cellulose (DEAE) at pH 8.0 and 7.0 with tris (hydroxymethyl) aminomethane (Tris) buffer were M antigens; those obtained at pH 4.0 and 4.0 with salt were H antigens. The four fractions had protein to carbohydrate ratios of 7.3, 14.0, 8.4, and 6.5 respectively, and all had essentially the same amino acid composition with no methionine and tyrosine and little histodine, arginine, phenylalanine and lysine. They had high concentrations of glucose, less mannose and traces of galactose. The low molecular weight fractions had the new complex "Y antigen", M antigen with protein to carbohydrate ratios of 1.4, 1.4 and 0.3 respectively. The amino acid and sugar composition of Y antigen strongly resembled the composition of the low molecular weight H and M antigens. Unlike the high molecular weight antigens, these low molecular weight antigens had methionine in relatively high concentrations; they had the same sugars as their respective high molecular weight counterparts. The yeast phase antigens differed from their respective mycelial counterparts in the following ways: glucose was the major sugar in the yeast phase with less amounts of mannose and traces of galactose, whereas in the mycelial antigens, mannose was the major sugar, with lesser amounts of galactose, and hexosamine. The H and M antigens of the yeast phase had high concentrations of glycine and alanine, whereas in the mycelial phase, these antigens had high concentrations of threonine and proline; the H and M antigens of the yeast phase had 5 to 16 times the protein to carbohydrate ratio observed for the same antigens of histoplasmin.

Amino Acids↗
PubMed1987

Comparison of purified acid phosphatase allozymes in Drosophila virilis: differences in carbohydrate content and composition of the allozymes.

Three acid phosphatase (EC 3.1.3.2) allozymes (ACPH1, ACPH2, and ACPH4) of Drosophila virilis show different activities as measured by electrophoretic techniques. Recently, it was suggested that these differences are attributable to the variable ability of the allozymes to be incorporated into lysosomes (Narise, S., Genet. Res. Cambr., 45:143, 1985). Immunoelectrophoresis demonstrated that the activity differences between these electrophoretic variants coincided with differences in the amount of the enzyme protein in soluble fractions but not in whole cell-free extracts. These results support the idea that acid phosphatase allozymes in D. virilis are cell-localization variants. We examined the problem by structural analysis of both the protein and the carbohydrate moieties of these allozyme glycoproteins, since lysosomal enzymes are known to become localized in lysosomes through their carbohydrate moieties. The three ACPH allozymes were purified to homogeneity from their respective homozygotes and compared with respect to amino acid composition and carbohydrate content and composition. Amino acid compositions were similar, while content and compositions of neutral sugars were significantly different. The neutral sugar content of ACPH1 was 9.2%; that of ACPH2, 21.0%; and that of ACPH4, 7.3%. A trace of hexosamines, but no N-acetylneuraminic acid, was found in the ACPH allozymes. Isoelectric points varied corresponding to their electrophoretic mobilities, which were not changed by treatment with alkaline phosphatase and neuraminidase.

Acid Phosphatase↗
PubMed1983

Mechanisms of the secretory and motor responses of the Brunner's gland region of the intestines to duodenal acidification.

The secretory and motor responses of the Brunner's gland region of the duodenum to luminal acidification were examined in rabbits anesthetized with urethan. Isomotic solutions of sodium chloride (pH 7.2) were perfused continuously through adjacent in situ segments. The pH of the perfusate of the proximal segment was changed to 2.0 for 30 min. Perfusion pressure (motor response) and volume and hexosamine concentration (secretory response) of the effluent were recorded for 3 h. The motor and secretory responses to luminal acidification were examined after intravenous (atropine) or intraluminal (lidocaine) pretreatment. Responses to intravenous infusions of serotonin or secretin were determined, also. Both atropine and lidocaine eliminated the initial motor and secretory responses of the proximal segment. Lidocaine eliminated the delayed secretory response of the distal segment. Serotonin caused initial motor and secretory responses, but secretin caused a delayed secretory response only. These results suggest that duodenal acidification elicits a two-phase increase in Brunner's gland secretion, the first being motor-dependent and the second motor-independent. The initial motor response was mediated by a local reflex composed of cholinergic and perhaps tryptaminergic receptors. The delayed secretory response was mediated by local and nonlocal, possibly hormonal, factors. Increased duodenal motility may provide a vehicle for the rapid expulsion of mucus, and thereby serve an important role in the function of the Brunner's glands.

Acid-Base Imbalance↗
PubMed1977

[Isolation and characterization of the placental protein pp5 (author's transl)].

The isolation and characterization of placemental protein PP5 is described. The purification was achieved by use of immunoadsorbents. From the tissue of one human term placenta an average amount of 15 mg PP5 can be extracted. PP5 apparently is specific for the placenta; it could not be detected in extracts from other human tissues. In sera from pregnant women PP5 is not present or only in trace amounts (less than 0.1 mg%). In the ultracentrifuge PP5 was found to have a sedimentation coefficient of 2.8 S and a molecular weight of 36,600 daltons. Electrophoretically the protein migrates as a fast beta1-globulin. The isoelectric point was determined to be 4.6. PP5 is a glycoprotein and contains 19.8% carbohydrates (hexoses 10.0%, hexosamine 4.4%, fucose 0.4%, sialic acid 5.0%). The amino acid composition of the protein is reported, too. PP5 was found to inhibit the activity of trypsin and plasmin; the biological role of this protein therefore may be the inhibition of proteases.

Female↗
PubMed1977

[Isolation and characterization of a new tissue protein (pp7) from human placentae (author's transl)].

The isolation and characterization of a new tissue protein (PP7) from human placentae is described. The placental protein PP7 is not specific for the placenta; it is found in relative high concentrations in other human tissues as well. Trace amounts of PP7 occur in erythrocytes, too. In sera this protein could not be detected with the gel diffusion test of Ouchterlony nor with the electroimmunoassay technique. PP7 has a molecular weight of around 40,000 daltons and is composed of two identical subunits which are non-covalently linked. In the ultracentrifuge PP7 sediments with 3.5 S. The isoelectric point was found to be 4.9. Electrophoretically the protein migrates in the range between alpha 2 and beta1-globulins. PP7 is a glycoprotein; its carbohydrate content amounts to 5.4% (hexoses 3.0%, Hexosamine 1.2%, Fucose 0.2%, sialic acid 1.0%). The amino acid composition of the protein is reported, too.

Erythrocytes↗
PubMed1978

Hyaluronic acid in the pulmonary secretions of patients with alveolar proteinosis.

Hyaluronic acid was the only glycosaminoglycan found in the pulmonary secretions of patients with alveolar proteinosis. The compound gave a hexouronate/hexosamine molar ratio of about 1:1. Glucosamine constituted over 98% of the hexosamines, the remaining being galactosamine. It moved as a single spot with the mobility of standard hyaluronic acid on cellulose acetate electrophoresis, and this spot disappeared after digestion with hyaluronidase. It was associated with small amounts of proteins, the major amino acids of which are aspartic acid, glutamic acid, glycine, alanine, and leucine.

Amino Acids↗
PubMed1980

Hyaluronic acid. An indicator of pathological conditions of human lungs?

Hyaluronic acid was the only glycosaminoglycan found in detectable amounts in the pulmonary secretions of patients with cystic fibrosis. The compound gave a hexuronate/hexosamines molar ratio of approximately 1. Glucosamine represented over 98% of the total hexosamines, the remainder being galactosamine. No hexoses or sulfate could be detected. It moved as a single spot with the mobility of standard hyaluronic acid on cellulose acetate electrophoresis and this spot disappeared after digestion with testicular hyaluronidase. It was associated with trace amounts of protein, the major amino acids of which are aspartic acid, glutamic acid, glycine, and alanine.

Amino Acids↗
PubMed1983

L-glutamine D-fructose-6-P aminotransferase regulation by glucose-6-P and UDP-N-acetylglucosamine.

L-Glutamine D-Fructose-6-P aminotransferase regulates hexosamine synthesis. An affinity purified human fibroblast aminotransferase and specific radioisotope assays developed by us were used to show an independent inhibition of the aminotransferase by Glucose-6-P. More interestingly, at concentration of UDP-N-Acetylglucosamine and glucose-6-P where either sugar has no independent inhibitory effect, there is an allosteric and significant inhibition of the aminotransferase.

Allosteric Regulation↗
PubMed1976

[Isolation and characterization of pregnancy associated alpha2 glycoprotein].

A method using immunoadsorbents for the isolation of pregnancy-associated alpha2-glycoprotein (alpha2-PAG) from the extract of human placentae is described. The physical properties and the chemical composition of the purified protein are determined: alpha2PAG sediments with 11,5 S, has a molecular weight of 360 000 daltons and is composed of subunits having a molecular weight of 180000, which are held together by disulfide bonds. The isoelectric point was found to be pH 4,7 and the extinction coefficient (E1%1cm) was determined to be 9,7 at 277 nm. The carbohydrate content of the molecule amounts to 12,1% (hexose 6,0%, hexosamine 3,7%, fucose 0,06%, sialic acid 2,4%). An analysis of the amino acids is reported, too. The purified alpha2PAG was used to determine the absolute concentrations of this protein in a reference standard and in sera.

Female↗
PubMed1977

Electron microscopy of cartilage proteoglycans.

The proteoglycans of cartilage are complex molecules in which chondroitin sulphate and keratan sulphate chains are covalently linked to a protein core, forming a polydisperse population of proteoglycan monomers. By interaction with hyaluronic acid and link proteins, the monomers form large macromolecular complexes. In vivo the proteoglycans mainly occur in such aggregates. In the electron microsope, the cartilaginous matrix can be seen to be made up of thin collagen fibrils and polygonal granules about 10-50 nm in diameter Addition of the polyvalent cationic dye Ruthenium Red to glutaraldehyde and osmium tetroxide fixatives yields a dense selective staining of the matrix granules. Following a short digestion of cartilage slices with either of the chondroitin sulphate-degrading enzymes hyaluronidase and chondroitinase or with the proteolytic enzyme papain, the matrix granules were few in number or completely absent and the proteoglycan content, measured as hexosamine, decreased by up to 90%. Similarly, extraction of the cartilage with 4 M guanidine-HCl removed all matrix granules and most of the proteoglycans. From these findings, it can be concluded that the matrix granules represent proteoglycans, most probably in aggregate form, and that Ruthenium Red staining may be used to study the distribution of these macromolecules in thin sections. As a complement to chemical studies on proteoglycan structure, it is also possible to observe and measure individual molecules in the electron microscope after spreading them into a monomolecular layer with cytochrome c. This technique has been applied in investigations on proteoglycans isolated from bovine nasal cartilage and other hyaline cartilages. The molecules in the monomer fractions appeared as an extended central core filament to which about 25--30 side-chain filaments were attached at various intervals. The core filament, averaging about 300 nm in length, was interpreted as representing the polysaccharide binding part of the protein core and the side-chain filaments, averaging about 45 nm in length, as representing the clusters of chondroitin sulphate chains. Statistical treatment of the collected data indicated that no distinct subpopulations existed within the monomer fractions. The electron microscopic results correlated well with chemical data for the corresponding fractions and together with recent observations on various aggregate fractions strongly support present concepts of proteoglycan structure.

Animals↗
PubMed1987

The effect of D-(+)-glucosamine on levels of free N-acetylneuraminic acid and UDP-N-acetylhexosamines in infantile sialic acid storage disease (ISSD) fibroblasts.

An impairment in the regulation of N-acetylneuraminic acid (NANA) biosynthesis might potentially contribute to accumulation of free NANA in fibroblasts of patients with sialic acid storage disease (ISSD). By the use of a glucosamine loading test an increase in uridine-diphosphate-N-acetyl-hexosamines (UDP-HexNAc) but not in free NANA was found. NANA biosynthesis therefore appears to be under normal regulatory control in ISSD.

Fibroblasts↗
PubMed1990

Histochemical studies of intestinal epithelial goblet cell glycoproteins during the development of the human foetus.

Histochemical studies performed on specimens of intestine from 12 to 37-week human foetuses showed that the epithelial glycoproteins of the goblet cells of the small intestine are non-sulphated sialoglycoproteins containing neutral sugar (hexose, 6-deoxy hexose or N-acetyl hexosamine residues with Periodic acid-Schiff (PAS) reactive vicinal diols), sialic acids without O-acyl substituents, smaller and variable quantities of sialic acids with O-acyl substituents at positions C8 or C9 (or with two or three side chain substituents) and O-acyl sugars (neutral sugars with an ester substituent blocking PAS reactivity). In the lower small intestine glycoproteins containing 8 (or 9)-O-acyl sialic acids are first observed in goblet cells at the tips of the villi. As the foetus matures their quantity increases and they are found in goblet cells located along the length of the villi. Smaller quantities of O-acyl sialic acids and traces of O-acyl sugars occur in the goblet cells of the upper small intestine. The colonic goblet cells contain sulphosialoglycoproteins of two types. The first type, found in the majority of specimens, contains O-sulphate ester, neutral sugar, O-acyl sugars and 8 (or 9)-O-acyl sialic acids. The second type contains O-sulphate ester, neutral sugars, and sialic acids which are either without side chain O-acyl substituents or are a mixture of such acids and 8 (or 9)-O-acyl sialic acids; O-acyl sugars are reduced or absent.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1977

Carbohydrate composition of the human cataractous lenses.

Specific chemical assays, including carbohydrate, hexosamines and hexuronic acid, were determined on the lens insoluble albumoid. It was noticed that the carbohydrate composition varies with age. The significance of carbohydrate in the lens is discussed.

Adult↗
PubMed1979

[Isolation and characterization of a new placenta specific protein (PP10) (author's transl)].

PP10 was isolated from aqueous extracts of human term placentae by fractionating the proteins with rivanol and ammonium sulfate, by gelfiltration on Sephadex G-150 and by use of immunoadsorbents. PP10 apparently is a protein specific for the placenta; it could not be detected in extracts from other human tissues. From one human term placenta an average amount of 20 mg PP10 can be extracted. In sera from pregnant women PP10 is usually present only in trace amounts (less than 0.1 mg/100 ml). PP10 has the electrophoretic mobility of an alpha1-globulin and an isoelectric point of 5.1. The purified protein sediments with 3.8 S. PP10 was found to have a molecular weight of 48,000 as determined by ultracentrifugation and a molecular weight of 65,000 as determined by SDS-PAA gel electrophoresis. PP10 is a glycoprotein containing 6.65% carbohydrates (hexoses 4.8%, hexosamines 1.2%, fucose 0.05%, sialic acid 0.6%). The amino acid composition of PP10 has been determined, too; the most abundant amino acids in this protein are glutamic acid, aspartic acid, leucine and alanine.

Electrophoresis↗
PubMed1980

[New placental protein (PP15) with immunosuppressive properties (author's transl)].

The isolation and characterization of a new placental protein (PP15) which has immunosuppressive properties are described. The protein was purified from extracts of human term placentae by rivanol and ammonium sulfate fractionation, gel filtration, ion exchange chromatography, preparative zone electrophoresis, and chromatography on hydroxyapatite. PP15 was found to have a sedimentation coèfficient of 2.9 S and a molecular weight of 30,700 daltons as determined by ultracentrifugation; its molecules apparently are composed of two identical subunits which are held together by non-covalent bonds. The electrophorectic mobility of PP15 corresponds to that of albumin. PP15 is a glycoprotein and contains 3.3% carbohydrates (hexoses 2.8%, hexosamines 0.3%, sialic acid 0.2%). The amino acid composition of this protein was also determined: the most abundant amino acids in the peptide chain were found to be glutamic acid, aspartic acid, isoleucine, and leucine. PP15 has immunosuprressive properties: on testing its effect on the lymphoycte transformation in the MLC-test in vitro a significant inhibitory activity could be demonstrated.

Aspartic Acid↗
PubMed1989

Biochemical and genetic studies on GP43, a 43-kD glycoprotein detected immunologically in human urine and serum.

A new and previously undescribed glycoprotein with a molecular weight of 43,000 has been isolated from human urine. This protein, designated GP43; copurified with ribonuclease, which has the same molecular weight, but ribonuclease activity was removed by passage through an affinity column of agarose-5'-(4-aminophenyl phosphoryl) uridine 2'(3') phosphate. GP43 contains about 5.9% neutral sugar, 2.3% hexosamine, and 1.6% sialic acid. A rabbit antibody to the purified GP43 reacted with human urine and serum as well as with the purified GP43. The genetic polymorphism of GP43 was then studied in desialylated human serum samples by urea-polyacrylamide gel isoelectric focusing, followed by immunoblotting with the specific antibody for GP43. Three common phenotypes, designated GP43 1, 1-2, and 2, were easily recognized using this technique and represented homozygosity or heterozygosity for two autosomal codominant alleles, GP43*1 and GP43/2. The frequencies of the GP43*1 and GP43*2 alleles in a Japanese population were 0.7683 and 0.2317, respectively.

Adult↗
PubMed1980

Influence of calcium depletion on medullary bone of laying hens.

Medullary bone of birds maintained on a low-calcium diet represents a good model to study modifications of matrix composition in calcified tissue undergoing intense formation and resorption. The composition of the bone matrix during the low-calcium diet has been analyzed by both chemical and histological techniques. Sixty White Leghorn pullets 1 year old were used for the experiment. Fifteen birds served as controls and were killed on day zero; the remaining birds were placed on a calcium-deficient diet (0.13% calcium) and sacrificed after 4, 7, and 12 days of treatment in groups of 15. Serum levels of calcium, PTH, and estrogens were also measured. Chemical analysis of the samples were made for total nitrogen, hydroxyproline, hexosamine, hexoses, calcium, and phosphorus. Collagen and proteoglycans of the matrix of medullary bone of the egg-laying hens were found to be affected by the low-calcium diet. They either increased or decreased during the experiment but never in parallel. The increment of serum PTH is considered responsible for the variations in the amount of collagen. The effects of this hormone are magnified by the fall of serum estrogens as shown also by variations in the amounts of noncollagenous protein. In the late phase of the diet the matrix is represented by poorly calcified osteoid tissue rich in noncollagenous protein, i.e., proteoglycans and glycoproteins.

Animals↗