scholarly journals Properties and N-terminal sequence of allophycocyanin from the unicellular rhodophyte Cyanidium caldarium

1977 ◽  
Vol 163 (3) ◽  
pp. 571-581 ◽  
Author(s):  
A S Brown ◽  
R F Troxler
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Phosphate Buffer ◽  
Alpha Helix ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Polyacrylamide Gels ◽  
Cyanidium Caldarium ◽  
N Terminus ◽  
Circular Dichroic

Allophycocyanin from the unicellular rhodophyte Cyanidium caldarium was purified by (NH4)2SO4 fractionation and ion-exchange chromatography on brushite (calcium phosphate) columns and on DEAE-Sephadex A-25 columns. The specific absorption coefficient (A0.1%1cm) at 650nm of purified allophycocyanin was 6.35 in 0.05M-potassium phosphate buffer, pH7.0. Absorption maxima of allophycocyanin occurred at 650, 618 (shoulder), 350 and 275 nm. Circular-dichroic spectra displayed positive-ellipticity bands at 658 and 630 nm and a major negative-ellipticity band at 340nm. Computer analysis of the circular-dichroic spectrum of allophycocyanin from 207 to 243 nm indicated 42% alpha-helix and 58% beta-form. The estimated molecular weight of purified allophycocyanin on calibrated Sephadex G-200 columns at pH7.0. was 196000. Electrophoretic examination of allophycocyanin on sodium dodecyl sulphate/polyacrylamide gels revealed a single band with apparent mol.wt. 16000. The presence of two polypeptide subunits, with nearly the same molecular weight, was revealed on polyacrylamide gels by using a modified electrophoresis buffer. Spectral analysis of the allophycocyanin subunits resolved by ion-exchange chromatography on Bio-Rex 70 columns indicated that a single phycocyanobilin chromophore was present on each polypeptide chain. Treatment of allophycocyanin with 8M-urea (pH3.0) and subsequent removal of urea by dialysis against water yielded a derivative phycobiliprotein with spectroscopic characteristics similar to those of phycocyanin. The original allophycocyanin spectrum was regenerated after incubation in phosphate buffer, pH7.0. Automated sequences analysis of the N-terminus of allophycocyanin showed that (a) the sequences of the two subunits were different from one another and were different from the subunits of phycocyanin from the same alga, (b) the subunits occurred in a molar ratio of 1:1 and (c) the sequences homology at the N-terminus among alpha- and beta-subunits of allophycocyanin from blue-green and red algae approached 90%.

scholarly journals Aminopeptidases in Webbing Clothes Moth Larvae. Properties and Specificities of Enzymes of Highest Electrophoretic Mobility

1975 ◽  
Vol 28 (6) ◽  
pp. 447 ◽  
Author(s):  
Colin W Ward
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Substrate Specificity ◽  
Metal Ions ◽  
Electrophoretic Mobility ◽  
Enzyme Inhibitors ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Polyacrylamide Gels ◽  
Tineola Bisselliella

The group of aminopeptidase bands from Tineola bisselliella larvae with highest electrophoretic mobility in polyacrylamide gels were purified further and partially separated by ion exchange chromatography. Three aminopeptidase bands were present in this material and were very similar with respect to their pH optima (7� 7), their molecular weight of 94000, their responses to metal ions and enzyme inhibitors and in their substrate specificity requirements.

A dipeptidylpeptidase secreted by Fasciola hepatica

Parasitology ◽  
1994 ◽  
Vol 109 (1) ◽  
pp. 113-118 ◽  
Author(s):  
C. Carmona ◽  
S. McGonigle ◽  
A. J. Dowd ◽  
A. M. Smith ◽  
S. Coughlan ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Liver Fluke ◽  
Fasciola Hepatica ◽  
Gel Filtration ◽  
Serine Proteinase ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Substrate Preference ◽  
Proteolytic Digestion

SUMMARYA dipeptidylpeptidase (DPP) was isolated from Fasciola hepatica by gel-filtration and ion-exchange chromatography. The exoproteinase is secreted by newly excysted juveniles, immature and mature flukes. The liver fluke DPP is a serine proteinase of molecular weight > 200 kDa and differs from previously characterized mammalian DPPs in its substrate preference and susceptibility to inactivation by inhibitors. The parasite DPP may function in the latter stages of the proteolytic digestion of host macromolecules. In this manner, the enzyme may be important in providing the parasite with dipeptides that could be absorbed through the intestine as nutrient.

scholarly journals A Polysaccharide Produced by Lactococcus lactis subsp. lactis YZ1 Isolated from Traditional Indonesian Fermented Milk, "Dadih"

2000 ◽  
Vol 1 (1) ◽  
pp. 1-5
Author(s):  
Yusdar Zakaria
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Lactococcus Lactis ◽  
Monosaccharide Composition ◽  
Fermented Milk ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Molar Ratio ◽  
Neutral Sugar ◽  
Glycoside Linkage

ABSTRACT.Lactococcus lactis subsp. Lactis YZI was isolated from M17 agar in which diluted Dadih was poured and incubated at 30 0C for 48 h. Taxonomix properties of the isolate were examined according to Bergey’s Manual of Systematic Bacteriologi and Manual for  Identification of Medical Bacteria. The isolation of polysaccharide from the precipitant was performed on an ion-exchange chromatography. The result showed that the polysaccharides produced by Lactococus lactis subsp. lactis YZI were neutral sugar (unadsorbrd fraction) and glycoconjugated (absorbed fraction). The neutral sugar had molecular weight of 10,000 and 20,000 with and α-glycoside linkage. The monosaccharide composition was mannose, glucose and galactose with a molar ratio of 1 :1,5 : 4,9.

scholarly journals High-Sulphur Proteins From a-Keratins ll. Isolation and Partial Characterization of Purified Components From Mouse Hair

1976 ◽  
Vol 29 (2) ◽  
pp. 11 ◽  
Author(s):  
Robert C Marshall ◽  
JM Gillespie
Keyword(s):  
Molecular Weight ◽  
Amino Acid ◽  
Ion Exchange ◽  
Amino Acid Composition ◽  
Acid Composition ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Fractional Precipitation ◽  
Molecular Weight Range

The present paper continues the study of the reduced and S-carboxymethylated high-sulphur proteins from mouse hair. Fractions have been obtained in a substantially purified form by fractional precipitation with ammonium sulphate at pH 6, followed by ion exchange chromatography on cellulose phosphate at pH 2�6. Approximately 80% by weight of the high-sulphur proteins fall into the ultra-high-sulphur category (carboxymethyicysteine content greater than 26 residues per 100 residues), and they cover a molecular weight range of 17000-28000. The components show a remarkable diversity in amino acid composition; for example the contents of arginine and glycine each vary by about 3 : 1. The remainder of the proteins contain 17-20 residues per 100 residues of carboxymethyicysteine, are smaller in size (molecular weight 11 500), and also show great diversity in overall amino acid composition.

scholarly journals The N-acetylhexosaminidase components of the ram testis and epididymis

1973 ◽  
Vol 133 (3) ◽  
pp. 593-599 ◽  
Author(s):  
Sarah Bullock ◽  
Bryan Winchester
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Isoelectric Focusing ◽  
Catalytic Properties ◽  
Deae Cellulose ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Multiple Forms ◽  
The Individual

Three and four N-acetylhexosaminidase components, from ram testis and epididymis respectively, have been separated by ion-exchange chromatography on DEAE-cellulose. Although they all have the same molecular weight (approx. 140000) and very similar catalytic properties towards the synthetic substrates, 4-methylumbelliferyl N-acetyl-β-glucosaminide and N-acetyl-β-galactosaminide, isoelectric focusing of the individual components showed that each had a distinct pI value. Isoelectric focusing has also been used to demonstrate the occurrence of multiple forms in ejaculated ram semen.

Comparative studies of manganese(II)-, nickel(II)-, zinc(II)-, copper(II)-, cadmium(II)-, and iron(III)-binding components in human cord and adult sera

1984 ◽  
Vol 62 (6) ◽  
pp. 449-455 ◽  
Author(s):  
Show-Jy Lau ◽  
Bibudhendra Sarkar
Keyword(s):  
Molecular Weight ◽  
Trace Metals ◽  
Ion Exchange ◽  
Comparative Studies ◽  
Gel Filtration ◽  
Deae Cellulose ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Low Molecular Weight ◽  
High Molecular Weight Proteins

The binding of six trace metals, Mn(II), Ni(II), Zn(II), Cu(II), Cd(II) and Fe(III), to human cord serum has been studied by Sephadex G-100 gel filtration at physiological pH, using radioisotopes as tracers. The results are compared with those obtained from adult serum. In both cord and adult sera, extensive amounts of the metals are bound to high molecular weight proteins. Among them, Fe(III) is mostly bound to transferrin; Ni(II), Zn(II), Cu(II), and Cd(II) are bound to albumin and other macro-molecules. The binding of Mn(II) either to transferrin or albumin is not resolved. Small fractions of Zn(II), Cu(II), and Cd(II) and large fractions of Mn(II) and Ni(II) are found to be associated with low molecular weight components of both sera. The distribution varies from metal to metal. However, the low molecular weight component of the size 1500 – 10 000 is present in all the metals studied. Further purification of this component was attempted by DEAE-cellulose ion-exchange chromatography. The possible identity as well as the biological role played by this particular component of serum in the transport of metals in blood and across membranes is discussed.

Purification and properties of an exocellular β-glucosidase of Candida molischiana (Zikes) Meyer and Yarrow capable of hydrolyzing soluble cellodextrins

1985 ◽  
Vol 63 (11) ◽  
pp. 1160-1166 ◽  
Author(s):  
Pierre Gondé ◽  
Robert Ratomahenina ◽  
Alain Arnaud ◽  
Pierre Galzy
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Gel Filtration ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Optimum Temperature ◽  
Purification And Properties ◽  
Optimum Ph

The exocellular enzyme β-glucosidase of Candida molischiana was studied. This strain is able to ferment soluble cellodextrins. The enzyme was partially purified by ion-exchange chromatography and gel filtration. The molecular weight of this enzyme was 120 000; its optimum pH was between 4 and 4.5 and its optimum temperature was 60 °C. This enzyme was active against different soluble glucosides and was inhibited by p-chloromercuribenzoate, gluconolactone, and glucose. A "glucosyltransferase" activity appeared in the presence of ethanol. The biosynthesis of the enzyme was constitutive but repressed by glucose.

scholarly journals The major proteoglycan of adult rabbit skeletal muscle. Relationship to small proteoglycans of other tissues

1991 ◽  
Vol 274 (1) ◽  
pp. 219-223 ◽  
Author(s):  
N Parthasarathy ◽  
L Chandrasekaran ◽  
M L Tanzer
Keyword(s):  
Skeletal Muscle ◽  
Ion Exchange ◽  
Gel Electrophoresis ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Rabbit Skeletal Muscle ◽  
Adult Rabbit ◽  
Bovine Bone ◽  
Adult Skeletal Muscle ◽  
N Terminus

We have been interested in examining the putative biological role(s) of the major proteoglycan of adult skeletal muscle. The small proteoglycans of adult rabbit skeletal muscle and tendon were extracted and purified by sequential density-gradient ultracentrifugation, ion-exchange chromatography and gel filtration. They appeared to be homogeneous by the criterion of gel electrophoresis in SDS and to yield one major product, the core protein, after digestion with chondroitin ABC lyase, also observed after gel electrophoresis. Two major products were obtained when the intact proteoglycans were cleaved by CNBr, and those peptides were separated by SDS/PAGE and by ion-exchange chromatography. Sequencing of the N-terminal amino acids of either the intact proteoglycans or the CNBr-cleaved products allowed for comparison of the muscle and tendon proteoglycan with derived amino acid sequences previously reported for bovine bone proteoglycan. The bone and tendon proteoglycan sequences were remarkably similar, whereas those of the muscle proteoglycan differed from the other two molecules. The major site of glycosaminoglycan substitution was on a peptide fragment distant from the N-terminus, and a presumptive serine residue at position 4 from the N-terminus also appeared to be substituted, perhaps with a small glycosaminoglycan chain. These results provide some insight into the diversity of small proteoglycans of the PG-II class and provide a basis for exploring their mode of genetic expression.

Separation and characterization of an α-glucosidase and maltase from Bacillus amyloliquefaciens

1985 ◽  
Vol 31 (8) ◽  
pp. 670-674 ◽  
Author(s):  
William M. Fogarty ◽  
Catherine T. Kelly ◽  
Sunil K. Kadam
Keyword(s):  
Molecular Weight ◽  
Ion Exchange ◽  
Growth Medium ◽  
Isoelectric Point ◽  
Bacillus Amyloliquefaciens ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Optimum Temperature ◽  
Ph Optimum

A novel α-glucosidase and a maltase were isolated from Bacillus amyloliquefaciens. The formation of both enzymes was induced by trehalose, sucrose, or lactose in the growth medium. Trehalose is by far the most efficient inducer of both systems. The α-glucosidase and maltase were separated and purified by ion-exchange chromatography on DEAE Bio-Gel A. Purified α-glucosidase hydrolysed p-nitrophenyl-α-D-glucoside, isomaltose, and isomaltotriose but sucrose, maltose, or related saccharides were not attacked. β-Glucosides and polymeric glucosides were not degraded. The optimum temperature for α-glucosidase activity was 40 °C and its pH optimum was 5.3. The molecular weight and isoelectric point (pI) of the enzyme were 27 000 and 4.6, respectively. Purified maltase attacked maltose and sucrose, while maltotriose and melezitose were hydrolysed at slower rates and p-nitrophenyl-α-D-glucoside was not degraded. Other properties of the maltase were as follows: optimum temperature for activity, 30 °C; pH optimum, 6.5; molecular weight, 64 000; and pI, 4.7.

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