scholarly journals Trypsin inhibitors in turnip (Brassica rapa L.) seeds

2014 ◽  
Vol 58 (4) ◽  
pp. 563-573 ◽  
Author(s):  
Anna Wilimowska-Pelc

A method of trypsin inhibitors isolation from turnip seeds is described. Inhibitors were extracted with 0.01 N HCI, concentrated by salting out with ammonium sulfate, and purified using ion-exchange chromatography on Sp-Sephadex C-25, QAE-Sephadex A-25 and affinity chromatography on immobilized trypsin. Among the three isolated inhibitors, ITR I of molecular weight 15.9 kDa, pl. 6,4, inhibited trypsin activity only. Inhibitors ITR II and ITR Ill inhibited also chymotrypsin activity, they had similar molecular weight (about 10 kDa), but their pI is 7.5 and over 10, respectively. Arginine residue occurred in P, position of the reactive site of inhibitors ITR I and ITR III, while in ITR 11 this position was occupied by lysine residue. Electrophoresis on polyacrylamide gel revealed that each inhibitor possessed two protein fractions, probably a virgin and modified form, with the reactive site peptide bond broken by trypsin.

1979 ◽  
Author(s):  
M.J. Lindhout ◽  
C. M. Jackson

In order to understand the function of activated factor V in the prothrombinase complex, we isolated the activation products obtained by action of thrombin and RVV-V on factor V and studied their functional properties. Factor V isolated from plasma by means of ion-exchange chromatography, a Ca-oxalate adsorption step and gelfiltration was homogenous in SDS-gelelectrophoresis (apparent MW 360,000, with and without reduction). Increase in factor V activity upon action by RVV-V is correlated with a single peptide bond cleavage, resulting in a 270,000 dalton and a 80,000 dalton component. Additional proteolysis of factor Va(RVV/V)’ by thrombin results in a further cleavage of the high MW component into peptides with MW's of 72,000, 94,000 and about 150,000 without a furth~r increase in factor V activity. Whereas none of the isolated peptides reveal factor Va activity, activity would be generated by a recombination in the presence of Ca2+ of the 94,000 MW or 270,000 MW component with the 80,000 component. Action of thrombin alone on factor V results in peptides of MW 72,000, 80,000, 94,000 and a peptide very rich in carbohydrate with an apparent MW of 150,000.


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.


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.


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.


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.


1976 ◽  
Vol 35 (03) ◽  
pp. 576-585 ◽  
Author(s):  
Katalin Váradi ◽  
Susan Elödi

SummaryHuman factor IXa was purified 5,000-fold from serum by ion exchange chromatography. The preparation was free from other clotting factors. Both pH sensitivity and heat stability of purified factor IXa appeared to be different from those of factor IX in the plasma. The molecular weight of human factor IXa is 80,000 as estimated from gel-filtration experiments. Modification of seryl or histidyl side chains abolished the activity of factor IXa.


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.


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