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N Parthasarathy

Publications and source records attributed to N Parthasarathy.

27 records · Page 2Linked to original sources
PubMed1982

Effect of diabetes on the glycosaminoglycan component of the human glomerular basement membrane.

The glycosaminoglycan (heparan sulfate) component of glomerular basement membranes from human kidneys of diabetic and nondiabetic subjects has been quantitated after isolation from protease digests of the membranes on DEAE-cellulose microcolumns. A significant decrease (P less than 0.005) in the glycosaminoglycan content of diabetic membranes was observed. Heparan sulfate was identified as the predominant glycosaminoglycan in both diabetic and control subjects and the extent of its sulfation appeared to be similar. The reduced level of glycosaminoglycan in the diabetic glomerular basement membrane was accompanied by a significant elevation of hexoses, which are primarily associated with the collagen component, suggesting that a redistribution of basement membrane macromolecules occurs in the diabetic state. Since heparan sulfate has been implicated as a major component of the glomerular anionic filtration barrier, its decreased content in diabetic basement membranes may contribute to the proteinuria observed in this disease.

Adult↗
PubMed1978

Hydroxyproline-rich glycoprotein in the seed coat of field bean.

1. The seed coats of field bean (Dolichos lablab var. lignosus) were found to contain bound hydroxyproline (0.26 g per 100 g dry weight) extractable in 30% with 5% trichloroacetic acid or in 90% with 10% potassium hydroxide. 2. The alkaline extract was fractionated by DEAE-cellulose chromatography into several hydroxyproline-containing fractions, composed of protein and carbohydrate in varying proportions. From the major fraction, a hydroxyproline-containing glycoprotein fraction was isolated by Sephadex G-200 chromatography. It gave a single band on agar-gel electrophoresis, and contained: protein (23.1%), arabinose (11.2%), galactose (13.4%), glucose (17.6%), mannose (22.6%) and uronic acids (11.3%). The content of hydroxyproline in the protein moiety was about 9%. Hydrolysis of the glycoprotein fraction with barium hydroxide yielded three components containing hydroxyproline and arabinose at the ratios of 1:2, 1:3 and 1:4.

Chromatography, DEAE-Cellulose↗
PubMed1976

Glycoprotein nature of tannase in Aspergillus niger.

1. Tannase (tannin acyl-hydrolase, EC 3.1.1.20) was isolated from the culture medium of Aspergillus niger and purified about 200-fold. On polyacrylamide-gel electrophoresis it gave a single band. 2. The molecular weight of the enzyme was of the order of 55 000 as determined by gel filtration. The enzyme contains 21.5% of carbohydrates (mannose and glucose). 3. Treatment of tannase with alkaline borohydride decreased the content of threonine, serine and mannose, suggesting that the carbohydrate-peptide linkage is of the O-glycoside type, involving mannose linked to threonine and serine.

Aspergillus↗
PubMedDate not supplied

Collagen biosynthesis in rabbit intraarticular patellar tendon transplants.

Autogenous patellar tendon grafts were transplanted into the knees of 40 New Zealand White adult rabbits. Grafts were subsequently analyzed for rate of collagen synthesis, collagen content, collagen type, histologic change, and cyanogen bromide cleavage patterns of collagen to closely assess the nature of collagen in tendon grafts up to 2 years from the time of transplantation. Tendon grafts were placed in rabbit knees as free fragments or were attached to synovium. These studies show that tendon grafts, even without vascularization or stress, remain viable after intraarticular transfer. Vascularization produces a trend toward increased collagen synthesis, but statistical analysis suggests that control levels of collagen synthesis continue after tendon transfers into rabbit knees. Cyanogen bromide cleavage peptides showed appropriate collagen formed by unstressed autogenous tendon transplants removed from rabbit knees up to 2 years from transplantation. All tendon grafts degenerated initially, but began to form histologically healthy looking connective tissue by 18 to 24 weeks after transplantation. Overall, the results are encouraging with regard to the fate of intraarticular tendon grafts.

Animals↗
PubMedDate not supplied

Isolation, characterization and nature of carbohydrate-peptide linkage of an alkali-extractable non-collagenous glycoprotein from albino rat skins.

A glycoprotein was isolated from young albino rat skins by alkali extraction under mild conditions and purified by Sephadex G-200 and DEAE-Sephadex A-50 chromatography. It was found to be homogeneous by agar gel electrophoresis. It had a molecular weight of approximately 90,000 and contained galactose, mannose, fucose, N-acetylglucosamine, N-acetylgalactosamine and sialic acids as its carbohydrate constituents. The release of sialic acids from the glycoprotein by neuraminidase indicated their terminal positions in the carbohydrate chains. The glycoprotein lacked hydroxyproline which indicates its non-collagenous nature. The treatment of the glycoprotein with alkaline borohydride resulted in the decrease of threonine, serine and N-acetylgalactosamine contents. The presence of O-glycosidic linkage of N-acetylgalactosamine with serine and threonine is therefore suggested.

Amino Acids↗