Changes in renal glomerular basement membrane with age and nephritis

1977 ◽  
Vol 55 (12) ◽  
pp. 1197-1206 ◽  
Author(s):  
N. Kalant ◽  
S. Satomi ◽  
R. White ◽  
E. Tel
Keyword(s):  
Amino Acid ◽  
Basement Membrane ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Glomerular Basement Membrane ◽  
Disulfide Bonds ◽  
Sodium Dodecyl ◽  
Collagen Content ◽  
Insoluble Residue ◽  
Adult Rats

Glomerular basement membrane was obtained from normal, young and old adult rats and from animals with antiserum nephritis, daunomycin nephrosis, and lathyrism. With increased age there was an increase in the collagen content of whole glomeruli and of the basement membrane. About 50% of the membrane protein was solubilized in 1% sodium dodecyl sulfate, and a further 35% was solubilized by reduction and alkylation. Inhibition of formation of collagen cross-links by induction of lathyrism did not affect membrane solubility. Preparative disc gel electrophoresis permitted separation of a number of components of different composition; with decreasing molecular weight the collagen content declined from almost 100% to 0%.In antiserum nephritis, there was an increase in the noncollagen components of the membrane and marked alterations in amino acid composition, both of whole membrane and of electrophoretically separated components. In daunomycin nephrosis, the amino acid composition was similar to that of antiserum nephritis. The solubility of membrane from nephritic rats was normal. The composition of the insoluble residue was similar for all membrane preparations and resembled pure collagen. It is suggested that the presence of abnormal noncollagen proteins, associated with the insoluble collagen core by hydrophobic and disulfide bonds, as in antiserum nephritis, is associated with increased membrane permeability leading to proteinuria.

scholarly journals Separation and partial characterization of guinea-pig caseins

1978 ◽  
Vol 173 (2) ◽  
pp. 633-641 ◽  
Author(s):  
R K Craig ◽  
D McIlreavy ◽  
R L Hall
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Guinea Pig ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Exchange Chromatography

1. Guinea-pig caseins A, B and C were purified free of each other by a combination of ion-exchange chromatography and gel filtration. 2. Determination of the amino acid composition showed all three caseins to contain a high proportion of proline and glutamic acid, but no cysteine. This apart, the amino acid composition of the three caseins was markedly different, though calculated divergence values suggest that some homology may exist between caseins A and B. Molecular-weight estimates based on amino acid composition were in good agreement with those based on sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. 3. N-Terminal analysis showed lysine, methionine and lysine to be the N-terminal residues of caseins A, B and C respectively. 4. Two-dimensional separation of tryptic digests revealed a distinctive pattern for each casein. 5. All caseins were shown to be phosphoproteins. The casein C preparation also contained significant amounts of sialic acid, neutral and amino sugars. 6. The results suggest that each casein represents a separate gene product, and that the low-molecular-weight proteins are not the result of a post-translational cleavage of the largest. All were distinctly different from the whey protein alpha-lactalbumin.

scholarly journals Studies on the subunits of human myeloperoxidase

1984 ◽  
Vol 222 (3) ◽  
pp. 701-709 ◽  
Author(s):  
R L Olsen ◽  
C Little
Keyword(s):  
Heat Treatment ◽  
Amino Acid ◽  
Molecular Mass ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Additional Species ◽  
Main Protein

The subunit composition of human myeloperoxidase was studied with the use of sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and gel filtration. The subunit pattern observed depended on the manner in which the enzyme was treated before analysis. Reduction before heat treatment in detergent led to two main protein species (Mr 57 000 and 10 500), whereas reduction during or after heat treatment yielded an additional species of Mr 39 000. Heating without any reductive pretreatment yielded the 39 000-Mr form as the major electrophoretic species. Carbohydrate staining showed large amounts of sugar on the 57 000-Mr species and little on the 10 500-Mr form. Significant amounts of haem were associated with this latter subunit. Haem also seemed to be associated with the 57 000-Mr form but not with the 39 000-Mr one. These three subunit forms were isolated and their amino acid composition analysed. The 57 000-Mr and 39 000-Mr forms had very similar amino acid composition and yielded an apparently identical collection of fragments on incubation with CNBr. Once separated, the subunits could not be interconverted. Generally, minor amounts of other molecular-mass forms were observed. The nature of the various molecular-mass forms originating from myeloperoxidase is discussed.

scholarly journals Purification and properties of a proteolytic enzyme from the cercariae of the human trematode parasite Schistosoma mansoni

1982 ◽  
Vol 201 (1) ◽  
pp. 137-144 ◽  
Author(s):  
W J Landsperger ◽  
M A Stirewalt ◽  
M H Dresden
Keyword(s):  
Amino Acid ◽  
Schistosoma Mansoni ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Isoelectric Point ◽  
Proteolytic Enzymes ◽  
Sodium Dodecyl ◽  
Skin Penetration ◽  
Cathepsin G ◽  
Trematode Parasite

Skin penetration by the cercarial stage of the human trematode parasite Schistosoma mansoni is mediated by the secretion of proteolytic enzymes able to digest components of mammalian connective tissues. In the present study the purification of these proteinases from cercarial homogenates is reported. The major proteinase species has a mol. wt. of approx. 25 000 and exists in monomeric form as determined by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. This proteinase has an isoelectric point of 6.0. Studies presented here, with a variety of substrates and inhibitors, confirm previous claims that these proteinases belong to the serine class, and, in addition, suggest that they resemble the vertebrate chymotrypsins rather than trypsins or elastases. However, the amino acid composition of the cercarial proteinase differs significantly from bovine chymotrypsin and from the human leucocyte chymotrypsin-like cathepsin G. The amino-acid-composition differences between these proteinases are consistent with their differences in isoelectric point. In order to obtain an insight into the role of the proteinase in skin penetration, its activity on cartilage proteoglycan monomers and on the isolated peptide backbone of proteoglycan was studied. The results of the present study indicate that the cercarial enzyme catalyses a limited specific digestion of the peptide core.

Toxaphene Effects on Growth and Bone Composition of Fathead Minnows, Pimephales promelas

1975 ◽  
Vol 32 (5) ◽  
pp. 593-598 ◽  
Author(s):  
Paul M. Mehrle ◽  
Foster L. Mayer Jr.
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Calcium Concentration ◽  
Pimephales Promelas ◽  
Collagen Content ◽  
Fathead Minnows ◽  
Bone Composition ◽  
Flow Through

Fathead minnows (Pimephales promelas) were exposed to toxaphene (55–1230 ng/liter) in a flow-through diluter system for 150 days. Growth was not affected by toxaphene for up to 90 days of exposure, but within 150 days it was significantly reduced at all concentrations. Collagen content of the backbone was decreased (P < 0.05), amino acid composition was changed, and calcium concentration was increased. Results from this study suggest that toxaphene altered the development and quality of the backbone, and induced biochemical manifestations of the "broken-back" syndrome. Radiographic analyses of the fish support our hypothesis that toxaphene induced a weakened, fragile backbone.

scholarly journals Species differences in the occurrence of copper-metallothionein in the particulate fractions of the liver of copper-loaded animals

1984 ◽  
Vol 219 (2) ◽  
pp. 539-546 ◽  
Author(s):  
R K Mehra ◽  
I Bremner
Keyword(s):  
Amino Acid ◽  
Physicochemical Properties ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Sodium Dodecyl Sulphate ◽  
Metal Content ◽  
Species Differences ◽  
Sodium Dodecyl ◽  
Pig Liver

Large amounts of Cu-metallothionein were obtained by 2-mercaptoethanol and sodium dodecyl sulphate extractions of the particulate fractions of the liver of pigs given high-Cu2+ diets or rats injected with Cu2+. Three isoproteins were purified from pig liver and characterized on the basis of their physicochemical properties, metal content and amino acid composition. No such pool of Cu-metallothionein was present in the liver of Cu2+-loaded sheep or of rats given Cu2+-supplemented diets.

Isolation, preparation and the amino acid composition of 4 milk-fat globule membrane proteins solubilized by treatment with sodium dodecyl sulphate

1976 ◽  
Vol 43 (3) ◽  
pp. 401-409 ◽  
Author(s):  
T. E. Cawston ◽  
M. Anderson ◽  
G. C. Cheeseman
Keyword(s):  
Amino Acid ◽  
Membrane Proteins ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Milk Fat ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Milk Fat Globule Membrane ◽  
Milk Fat Globule ◽  
Fat Globule

SummaryMilk-fat globule membrane (MFGM) proteins were solubilized by treatment with SDS. Four of the major proteins were isolated as SDS complexes using column chromatography. The purity of each isolate was determined by SDS polyacrylamide gel electrophoresis and sufficient of each protein was obtained for amino acid analysis. The amino acid compositions of the isolated MFGM proteins and a total MFGM protein extract were determined. Differences in amino acid composition were found in particular between the major MFGM glycoprotein and the other 3 membrane proteins. The relationships of the amino acid composition to protein properties and structure are discussed.

Characterization of amylases produced by tumors.

1981 ◽  
Vol 27 (4) ◽  
pp. 556-559 ◽  
Author(s):  
T Takeuchi ◽  
H Fujiki ◽  
T Kameya
Keyword(s):  
Amino Acid ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Tertiary Structure ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Relative Molecular Mass ◽  
Major Peak ◽  
Salivary Amylase ◽  
A Minor

Abstract Amylases were purified and characterized from three amylase-producing human tumors. The relative molecular mass of the amylases was estimated to be 54 000 on sodium dodecyl sulfate/polyacrylamide gel electrophoresis, different from human salivary amylase (61 000 and 64 000) and human pancreatic amylase (60 000). The tumor amylases had completely identical antigenicities with human salivary and pancreatic amylases against antibody to human salivary amylase, while the intensity of the tumor amylases was less than 20% of that of human salivary and pancreatic amylases on single radial immunodiffusion. On isoelectric focusing, two of the three tumor amylases showed a major peak at pH 6.4, which corresponded to a major peak of human salivary amylase, the other showed a major peak at pH 6.4, which corresponded to a minor peak of human salivary amylase. The three tumor amylases showed similar amino acid composition, different from those of human salivary and pancreatic amylases. These findings suggest that tumor amylases have a tertiary structure similar to that of normal human amylases, but differ from them in amino acid composition.

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