Biomedical subjects

H Munakata

Publications and source records attributed to H Munakata.

102 records · Page 6Linked to original sources

PubMed1980

Chemical nature of human urinary glycosaminoglycans.

To elucidate precise chemical nature of urinary glycosaminoglycans (GAG), GAG in the seven major acidic subfractions in a previous paper (Endo et al. 1980a) were analyzed for the chemical compositions and studied on the linkage between carbohydrate and peptide. All the subfractions examined contained galactosamine, hexuronic acid as the major constituent sugars, and xylose, galactose, L-fucose as the minor ones. Some of the subfractions contained additional glucosamine. Sulfate was also found in all the subfractions as their major constituent. The contents of total amino acids ranged from 1.20 to 17.9%. Serine, threonine, aspartic acid, glutamic acid, glycine, alanine and leucine were found as major amino acids. Pronase digestion did not significantly change their molecular size. The presence of O-xylosyl-serine linkage between carbohydrate chains and peptide moieties ws verified byan alkali treatment. Nevertheless, the presence of small portions of galactose and xylose residues at the reducing ends of the carbohydrate chains suggested a possibility of exertion of endo-beta-galactosidase and endo-beta-xylosidase activities for the linkage regions.

Amino Acids↗

PubMed1980

Extraction of hyaluronic acid from rabbit skin with lanthanum chloride.

The defatted rabbit skin was extracted with 0.5 M LaCl3, and the extract was dialyzed exhaustively against distilled water. The precipitate formed during dialysis was dissolved in 28 mM EDTA (ethylenediamine tetraacetate) (pH 7.0). Fr A was obtained from the solution by precipitation with ethanol in the presence of sodium acetate. The results of gel filtration on Sepharose 4B, electrophoresis on cellulose acetate membrane before and after digestion with Streptomyces hyaluronidase, and analytical data indicated that Fr. A was hyaluronic acid with high molecular weight. The present observation together with previous findings suggest that the binding status of proteoglycans in the skin differs significantly from that in cartilages.

Animals↗

PubMed1978

Hormonal effects on the biosynthesis of sulfated glycoprotein in a microsomal fraction of the endometrium of rabbit uterus.

A crude microsomal fraction (M-Fr) was separated from the endometrial scrapings of uteri of ovariectomized rabbits with or without hormonal treatment. The effects of estrogen and progesterone on the incorporation into M-Fr of L-[U-14C]-fucose and N-acetyl-D-[6-3H]-glucosamine from their nucleotides were investigated. Estrogen increased the incorporation of these sugars, whereas progesterone suppressed this effect. The results of fractionation on a DEAE-Sephadex A-25 (Cl- form) column of the isotope-labelled complex saccharide mixtures, obtained by pronase digestion of the incubation mixtures, indicated that biosynthesis of sulfated glycoprotein was most sensitive to the hormones among the complex saccharides in M-Fr. Thus, a hormonal effects on the biosynthesis of sulfated glycoprotein in the endometrium of ovariectomized rabbit has been unambiguously confirmed at the microsomal level.

Acetylglucosamine↗

PubMed1978

Isolation and characterization of a sulfated glycoprotein from rabbit small intestine.

Complex saccharides were extracted with 0.9% NaCl at 0 degrees C from rabbit small intestine, then fractionated with cetylpryridinium chloride (CPC), followed by DEAE-Sephadex A-25 column chromatography and by GEON-zone electrophoresis. An acidic glycoprotein (Fr. A-1) thus obtained was shown to be homogeneous by electrophoreses on cellulose acetate membrane and on sodium dodecyl sulfate (SDS)-polyacrylamide gel, as well as by gel filtration on Sepharose 4B. It contained 40.0% protein, 52.7% carbohydrate, and 1.6% sulfate. The principal sugars in the sulfated glycoprotein were galactose, glucosamine, galactosamine, and sialic acid. Small quantities of mannose, L-fucose, and glucose were also present. Glutamic acid, threonine, aspartic acid, alanine, serine, leucine, proline, glycine, valine, and histidine were the major amino acids of the protein moiety. Small amounts of other basic amino acids, sulfur-containing amino acids and aromatic amino acids were also present.

Amino Acids↗

PubMed1978

Study on the porcine tubular basement membrane.

Porcine kidney slices were gently homogenized with 0.9% NaCl in a Waring blender, followed by sieving of the homogenate to isolate tubules. The tubular basement membrane (TBM) was then prepared from the tubules by sonication in 1.0 M NaCl. Electron micrographs indicated a high degree of purity of the TBM with negligible contamination of fibrillar collagen. Analytical data showed that the TBM was a glycoprotein containing approximately 10% of carbohydrates. Of the sugar components, glucose and galactose comprised approximately 70% of the total carbohydrates and glycosylgalactosylhydroxylysine was detected in an alkaline hydrolyzate of the TBM. Besides them, mannose, fucose, glucosamine, galactosamine and sialic acid were also detected. The protein portion of the TBM contained hydroxyproline, hydroxylysine, half cystine, methionine and a large amount of glycine as the characteristic amino acids. Polyacrylamide gel-electrophoresis of the TBM gave 15 bands.

Amino Acids↗

PubMed1978

Composition of acidic glycoconjugates (glycosaminoglycans and glycoprotein) in myometrium of rabbit uterus under estrogenic condition.

Acidic glycoconjugates (glycosaminoglycans and glycoprotein) were obtained, from myometrium of ovariectomized rabbit under estrogenic condition, by pronase digestion, fractionation with cetylpyridinium chloride and Dowex I column chromatography, in succession. Composition of acidic glycoconjugates was determined enzymatically, employing Streptomyces hyaluronidase, chondroitinase AC II, chondroitinase ABC and crude heparinase. Each glycoconjugate was distributed in 3 approximately 8 fractions obtained by Dowex I column chromatography, indicating its charge and/or molecular heterogeneity. Acidic glycoconjugates consisted of hyaluronic acid (13.4%), chondroitin sulfates A plus C (39.4%), dermatan sulfate (24.6%), heparan sulfate (18.7%) and acidic glycoprotein (most probably sialoglycoprotein) (3.9%). Composition of acidic glycoconjugates in myometrium differed remarkably from that in whole uterus. Myometrium was abundant in chondroitin sulfate isomers (chondroitin sulfates A plus C plus dermatan sulfate), but lacked sulfated glycoprotein. The present results suggested that myometrium and endometrium of uterus may play quite different roles in reproduction.

Animals↗

PubMed1975

Comparison of the chemical composition of glomerular and tubular basement membranes obtained from human kidneys of diabetics and non-diabetics.

Glomerular basement membrane (GBM) and tubular basement membrane (TBM) were prepared from human kidneys of diabetics and non-diabetics, and their chemical composition was compared. GBM from diabetics contained a larger amount of hydroxyproline than that from non-diabetics, and smaller amounts of half-cystine, glucose, mannose and sialic acid. On the other hand, TBM from diabetics contained larger amounts of hydroxylysine, methionine, galactose, hexosamine and phospholipid phosphorus than non-diabetics, and smaller amounts of half-cystine, valine, leucine, lysine and histidine. No significant difference was observed in the contents of other components examined in this study between the corresponding membrane obtained from diabetics and non-diabetics. The observed changes may be due to alteration of the tissues in diabetes mellitus.

Adult↗

PubMed1975

Chemical compositions of glomerular and tubular basement membranes of human kidney.

Glomerular basement membranes (GBM) and tubular basement membranes (TBM) were prepared from human kidney and their chemical compositions were studied. Electron microscopic figures showed no contamination of the cellular components components or collagen fibers, indicating a high degree of purity of the preparations. Low contents of phospholipid supported this indication. Amino acid compositions of the human GBM and TBM resembled that of the bovine GBM, containing hydroxyproline, hydroxylsine, half-cystine, methionine and a large amount of glycine as the characteristic amino acids. The human GBM and TBM had similar carbohydrate compositions consisting of glucose and galactose, as the major sugars, together with mannose, L-fucose, hexosamine and sialic acid. Glucosylgalactosylhydroxylysine and a small amount of galactosylhydroxylysine were detected in alkaline hydrolyzates of both membranes. The human GBM and TBM separated into more than ten subunits having molecular weights ranging from 2.5 times 10-4 to more than 2.5 times 10-5 on polyacrylamide gel electrophoresis in the presence of sodium laurylsulfate and 2-mercaptoethanol. The electrophoretograms of both membranes resembled that of the bovine GBM. These observations indicate that the human TBM has a similar chemical structure to those of the human GBM and the bovine GBM.

Adult↗

PubMed1971