scholarly journals Jacaratia corumbensis O. Kuntze a new vegetable source for milk-clotting enzymes

2009 ◽  
Vol 52 (1) ◽  
pp. 1-9 ◽  
Author(s):  
Ana Rodrigues Duarte ◽  
Débora Maria Rodrigues Duarte ◽  
Keila Aparecida Moreira ◽  
Maria Taciana Holanda Cavalcanti ◽  
José Luiz de Lima-Filho ◽  
...  

The partial characterization and purification of milk clotting enzyme obtained from the (root latex) of Jacaratia corumbensis O. kuntze was studied, by fractional precipitation with ammonium sulphate and ion exchange chromatography. The ammonium sulphate precipitate showed five fractions (AS1- 0-20%; AS2 - 20-40%; AS3 - 40-60%; AS4 - 60-80%; AS5 - 80-100%) and among the fractions obtained, the 40-60% fraction (AS3) showed the highest milk clotting activity with a purification factor of 1.2 fold in relation to the crude extract. This fraction when applied on Mono Q column yielded two protein peaks (p1 and p2), but p1 pool showed the best milk-clotting activity. The optimal pH for the crude and partially purified extract was 6.5 and 7.0, respectively. The maximum milk-clotting activity was at 55ºC for the both crude and partially purified extracts. The enzyme was inhibited by iodoacetic acid which suggested that this enzyme was a cysteine protease, with molecular weight of 33 kDa.

1976 ◽  
Vol 29 (2) ◽  
pp. 11 ◽  
Author(s):  
Robert C Marshall ◽  
JM Gillespie

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.


Author(s):  
Yoko Takyu ◽  
Taro Asamura ◽  
Ayako Okamoto ◽  
Hiroshi Maeda ◽  
Michio Takeuchi ◽  
...  

Abstract Aspergillus oryzae RIB40 has 11 aspartic endopeptidase genes. We searched for milk-clotting enzymes based on the homology of the deduced amino acid sequence with chymosins. As a result, we identified a milk-clotting enzyme in A. oryzae. We expected other Aspergillus species to have a homologous enzyme with milk-clotting activity, and we found the most homologous aspartic endopeptidase from A. luchuensis had milk-clotting activity. Surprisingly, two enzymes were considered as vacuole enzymes according to a study on A. niger proteases. The two enzymes from A. oryzae and A. luchuensis cleaved a peptide between the 105Phe-106Met bond in κ-casein, similar to chymosin. Although both enzymes showed proteolytic activity using casein as a substrate, the optimum pH values for milk-clotting and proteolytic activities were different. Furthermore, the substrate specificities were highly restricted. Therefore, we expected that the Japanese traditional fermentation agent, koji, could be used as an enzyme source for cheese production.


1972 ◽  
Vol 130 (1) ◽  
pp. 211-219 ◽  
Author(s):  
Colin H. Self ◽  
P. David J. Weitzman

Two isoenzymes of NADP-linked isocitrate dehydrogenase have been identified in Acinetobacter lwoffi and have been termed isoenzyme-I and isoenzyme-II. The isoenzymes may be separated by ion-exchange chromatography on DEAE-cellulose, by gel filtration on Sephadex G-200, or by zonal ultracentrifugation in a sucrose gradient. Low concentrations of glyoxylate or pyruvate effect considerable stimulation of the activity of isoenzyme-II. The isoenzymes also differ in pH-dependence of activity, kinetic parameters, stability to heat or urea and molecular size. Whereas isoenzyme-I resembles the NADP-linked isocitrate dehydrogenases from other organisms in having a molecular weight under 100000, isoenzyme-II is a much larger enzyme (molecular weight around 300000) resembling the NAD-linked isocitrate dehydrogenases of higher organisms.


1959 ◽  
Vol 37 (8) ◽  
pp. 961-973 ◽  
Author(s):  
H. L. A. Tarr

Comparatively pure phosphoriboisomerase and ribulose 5′-phosphate 3′-epimerase enzyme preparations were obtained from lingcod muscle by a simple procedure involving water extraction, saturation of the extract with ammonium sulphate, dialysis, brief heating to 55 °C, lyophilization of the solution, and final separation by ion exchange chromatography, using diethylamiuoethyl cellulose columns. Both enzymes have broad pH optima above pH 7.0, but are rapidly inactivated below this value. The following equilibria were established and compared with those obtained by other investigators: [Formula: see text], 1.35:1.0; [Formula: see text], 1: 1.5 and [Formula: see text], 1:0.58:0.66. The ketopentulose phosphate resulting from the action of phosphoriboisomerase on D-ribose 5-phosphate was isolated and identified as D-ribulose5-phosphate. Both D-ribulose and D-xylulose were demonstrated after subjecting a product of epimerase action to hydrolysis by acid phosphatase and ion exchange chromatography.


The Analyst ◽  
2018 ◽  
Vol 143 (24) ◽  
pp. 5987-5998 ◽  
Author(s):  
Drishya Rajan Parachalil ◽  
Brenda Brankin ◽  
Jennifer McIntyre ◽  
Hugh J. Byrne

This study explores the potential of Raman spectroscopy, coupled with multivariate regression techniques and ion exchange chromatography, to quantitatively monitor diagnostically relevant changes in high molecular weight proteins in liquid plasma.


1981 ◽  
Author(s):  
H R Lijnen ◽  
B Wiman ◽  
B Van Hoef ◽  
D Collen

α2-Antiplasmin (α2AP), the main physiological inhibitor of plasmin in human plasma, is a single–chain glycoprotein with a molecular weight of 67,000 consisting of about 510 amino acids and containing 13 percent carbohydrate.A tryptic digest on 400 mg of reduced, carboxymethylated and citraconylated purified α2AP was performed. Peptides were separated by combinations of ion exchange chromatography, gel filtration and high performance liquid chromatography, and sequenced using the manual Edman degradation. Some peptides were further digested in order to establish overlaps. At the time of submission of this abstract we have sequenced 7 out of the approximately 21 arginyl peptides completely (each between 3 and 21 residues) and are working on the others. At present we have about 200 residues of sequence. Here we only report the stretches of 10 amino acids or more, which may be useful to compare the structure of α2AP with that of other serine protease inhibitors.


Parasitology ◽  
1994 ◽  
Vol 109 (1) ◽  
pp. 113-118 ◽  
Author(s):  
C. Carmona ◽  
S. McGonigle ◽  
A. J. Dowd ◽  
A. M. Smith ◽  
S. Coughlan ◽  
...  

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.


1975 ◽  
Vol 53 (3) ◽  
pp. 479-492 ◽  
Author(s):  
J. M. Trifaró ◽  
J. Dworkind

Adenosine triphosphate (ATP) induces the release of catecholamines, endogenous ATP, and soluble protein from chromaffin granules isolated from the adrenal medulla. When ATP exerts this action, it is hydrolyzed by enzymes present in the granule membrane, and part of the Pi liberated from ATP is transferred to the protein and lipid of the granule membrane. The phosphorylated lipid component, which was identified by thin-layer and ion-exchange chromatography as diphosphatidylinositol, was formed from ATP and monophosphatidylinositol. This latter phospholipid was the substrate for the enzyme phosphatidylinositol kinase. Both substrate and enzyme are components of the granule membranes, because they have a similar subcellular distribution as dopamine β-hydroxylase (a granule membrane marker). The formation of diphosphatidylinositol was Mg2+-dependent, it was further stimulated by Mn2+, it was inhibited by N-ethylmaleimide and the reaction had an optimal pH of 5. The synthesis of diphosphatidylinositol was also shown to occur in chromaffin granules "in situ" during the stimulation of the adrenal medulla by acetylcholine.


1977 ◽  
Vol 73 (2) ◽  
pp. 321-329 ◽  
Author(s):  
S. HARVEY ◽  
C. G. SCANES

SUMMARY Chicken growth hormone has been isolated from adenohypophysial tissue from which the glycoprotein hormones had been removed. The procedure entailed alkali extraction, ammonium sulphate precipitation and ion-exchange chromatography on DEAE-cellulose. The resulting fraction was homogeneous, active in the rat tibia bioassay and had a similar isoelectric point, molecular weight and amino acid composition to mammalian growth hormone. A specific homologous radioimmunoassay has been developed using the avian growth hormone.


2000 ◽  
Vol 1 (1) ◽  
pp. 1-5
Author(s):  
Yusdar Zakaria

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.


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