scholarly journals Partial purification of trypsin inhibitors from Parkia seeds (Fabaceae)

Hoehnea ◽  
2014 ◽  
Vol 41 (2) ◽  
pp. 181-186 ◽  
Author(s):  
Larissa Ramos Chevreuil ◽  
José Francisco de Carvalho Gonçalves ◽  
Leonardo de Azevedo Calderon ◽  
Luiz Augusto Gomes de Souza ◽  
Silvana Cristina Pando ◽  
...  

Leguminous seeds (Fabaceae) have a high content of inhibitors of which serine protease inhibitors are the most widely studied. However, there are only a few studies related to the investigation of these proteins in tree species belonging to the Amazon flora. The protein content presented in seeds of four Amazonian Leguminosae species, Parkia pendula, P. discolor, P. multijuga and P. Nitida, was extracted by using NaCl 0.15 mol L-1 and then partially fractionated by using affinity chromatography performed on a trypsin-Sepharose 4B. These inhibitors presented different affinities between trypsin and chymotrypsin serine proteases, showing a higher inhibition to trypsin compared to chymotrypsin, except for P. nitida, which showed high inhibition against both enzymes. The SDS-PAGE analysis showed that the species from Parkia genus have a main band corresponding to partially purified trypsin inhibitors. The apparent molecular mass inhibitors (approximately 13-18 kDa) and the high specificity for trypsin suggest the occurrence of Bowman-Birk and Kunitz type inhibitors.

1997 ◽  
Vol 78 (04) ◽  
pp. 1193-1201 ◽  
Author(s):  
Saulius Butenas ◽  
Maria E DiLorenzo ◽  
Kenneth G Mann

SummarySelective, sensitive assays for the quantitation of serine proteases involved in coagulation and fibrinolysis have been developed employing fluorogenic substrates containing a 6-amino-1-naphthalenesulfonamide leaving group (PNS-substrates). Over one hundred substrates were evaluated for hydrolysis by the serine proteases of blood coagulation and fibrinolysis, and substrate structure-efficiency correlations were examined. PNS-substrates which contain Lys in the P1 position are specific for Lys-plasmin and are either not hydrolyzed or hydrolyzed at a relatively low rate by factor Xa, thrombin, or urokinase-type plasminogen activator (uPA). These substrates allow quantitation of Lys-plasmin at concentrations as low as 1 pM. Eighteen of over 90 substrates tested for factor XIa are hydrolyzed by this enzyme at a relatively high rate reaching a kcat value of 170 s-1 and allowing quantitation of factor XIa at 10 fM. Eighteen of almost 90 PNS-substrates tested display high specificity for thrombin, some exceeding that for factor Xa by > 10,000-fold and > 100-fold for activated protein C (APC). Seven of these substrates have a over 100 s-1 and three of them have a KM below 1 μM. They allow the quantitation of thrombin at concentrations as low as 20 fM. For APC, uPA and the factor Vila/tissue factor complex, quantitation is feasible at 1 pM concentration. For factor Xa and factor VIIa the limits are 0.4 pM and 40 pM respectively. The PNS-substrates presented in this study may be employed for the development of direct and sensitive serine protease assays.


2014 ◽  
Vol 81 (3) ◽  
pp. 1024-1031 ◽  
Author(s):  
Bhagyalakshmi Kalidass ◽  
Muhammad Farhan Ul-Haque ◽  
Bipin S. Baral ◽  
Alan A. DiSpirito ◽  
Jeremy D. Semrau

ABSTRACTIt is well known that copper is a key factor regulating expression of the two forms of methane monooxygenase found in proteobacterial methanotrophs. Of these forms, the cytoplasmic, or soluble, methane monooxygenase (sMMO) is expressed only at low copper concentrations. The membrane-bound, or particulate, methane monooxygenase (pMMO) is constitutively expressed with respect to copper, and such expression increases with increasing copper. Recent findings have shown that copper uptake is mediated by a modified polypeptide, or chalkophore, termed methanobactin. Although methanobactin has high specificity for copper, it can bind other metals, e.g., gold. Here we show that inMethylosinus trichosporiumOB3b, sMMO is expressed and active in the presence of copper if gold is also simultaneously present. Such expression appears to be due to gold binding to methanobactin produced byM. trichosporiumOB3b, thereby limiting copper uptake. Such expression and activity, however, was significantly reduced if methanobactin preloaded with copper was also added. Further, quantitative reverse transcriptase PCR (RT-qPCR) of transcripts of genes encoding polypeptides of both forms of MMO and SDS-PAGE results indicate that both sMMO and pMMO can be expressed when copper and gold are present, as gold effectively competes with copper for binding to methanobactin. Such findings suggest that under certain geochemical conditions, both forms of MMO may be expressed and activein situ. Finally, these findings also suggest strategies whereby field sites can be manipulated to enhance sMMO expression, i.e., through the addition of a metal that can compete with copper for binding to methanobactin.


Author(s):  
Mi Li ◽  
Jaroslav Srp ◽  
Michael Mareš ◽  
Alexander Wlodawer ◽  
Alla Gustchina

Structures of BbKI, a recombinant Kunitz-type serine protease inhibitor from Bauhinia bauhinioides, complexed with human kallikrein 4 (KLK4) were determined at medium-to-high resolution in four crystal forms (space groups P3121, P6522, P21 and P61). Although the fold of the protein was virtually identical in all of the crystals, some significant differences were observed in the conformation of Arg64 of BbKI, the residue that occupies the S1 pocket in KLK4. Whereas this residue exhibited two orientations in the highest resolution structure (P3121), making either a canonical trypsin-like interaction with Asp189 of KLK4 or an alternate interaction, only a single alternate orientation was observed in the other three structures. A neighboring disulfide, Cys191–Cys220, was partially or fully broken in all KLK4 structures. Four variants of BbKI in which Arg64 was replaced by Met, Phe, Ala and Asp were expressed and crystallized, and their structures were determined in complex with KLK4. Structures of the Phe and Met variants complexed with bovine trypsin and of the Phe variant complexed with α-chymotrypsin were also determined. Although the inhibitory potency of these variant forms of BbKI was lowered by up to four orders of magnitude, only small changes were seen in the vicinity of the mutated residues. Therefore, a totality of subtle differences in KLK4–BbKI interactions within the fully extended interface in the structures of these variants might be responsible for the observed effect. Screening of the BbKI variants against a panel of serine proteases revealed an altered pattern of inhibitory specificity, which was shifted towards that of chymotrypsin-like proteases for the hydrophobic Phe and Met P1 substitutions. This work reports the first structures of plant Kunitz inhibitors with S1-family serine proteases other than trypsin, as well as new insights into the specificity of inhibition of medically relevant kallikreins.


2018 ◽  
pp. 52-58

Purificación Parcial y Caracterización de Alfa Amilasa de granos germinados de Chenopodium quinoa (Quinua) Partial Purification and Characterization of Alpha Amylase from germinated grains from Chenopopdium quinoa (Quinua) Melissa Bedón Gómez, Oscar Nolasco Cárdenas, Carlos Santa Cruz C. y Ana I. F. Gutiérrez Román Universidad Nacional Federico Villarreal, Facultad de Ciencias Naturales y Matemática, Laboratorio de Bioquímica y Biología Molecular, Jr. Río Chepén S/N, El Agustino. Telefax: 362 - 3388 DOI: https://doi.org/10.33017/RevECIPeru2013.0007/ Resumen Las alfa amilasas son las enzimas más estudiadas e importantes en el campo biotecnológico e industrial; ya que han reemplazado por completo la hidrólisis química del almidón. Estas enzimas son imprescindibles en la elaboración de productos alimenticios, combustibles, medicamentos y detergentes con la finalidad de optimizar procesos y conservar el medio ambiente. La α-amilasa puede ser purificada de diferentes organismos como plantas, animales, hongos y bacterias; actualmente un gran número de α-amilasas bacterianas en especial del género Bacillus están disponibles comercialmente y son las más utilizadas en las industrias. Sin embargo, la producción de éstas no satisfacen los requerimientos industriales en el mundo; ya que, la demanda de esta enzima se ha incrementado en los últimos dos años y el empleo de α-amilasas bacterianas ha provocado alergias afectando al 15% de la población a nivel mundial. . En este estudio, como fuente de α-amilasa se emplearon semillas de Chenopodium quinoa (quinua) var hualhuas blanca durante el proceso de germinación; esta enzima fue parcialmente purificada por precipitación con sulfato de amonio obteniendo una actividad específica final de 35.60U/mg y un grado de purificación de 5 veces. La purificación fue confirmada por SDS-PAGE, encontrando un peso molecular de 44kDa. La actividad enzimática se evaluó mediante el método de Miller mostrando máxima actividad a pH 7 y a temperatura de 37ºC. La linealización de Lineweaver-Burk nos dio un Km de 16mg/mL y Vmax de 100µM de maltosa/min. Por lo tanto, esta caracterización reúne los pre-requisitos necesarios para la aplicación en la industria. Descriptores: Chenopodium quinoa, alfa amilasa, germinación, purificación parcial. Abstract The alpha amylases are the enzymes most studied and important in biotechnology and industry; because they have completely replaced the starch’s chemical hydrolysis. These enzymes are essential in the food production, medicines and detergents in order to optimize processes and conserve the environment. The α-amylase can be isolated from different organisms such as plants, animals, fungi and bacteria, now a large number of bacterial α-amylases especially from genus Bacillus are commercially available and they are the most used in industry. However, the production of these do not meet industry requirements in the world, because the demand for this enzyme has increased in the last two years and the use of bacterial α-amilase has caused allergies affecting the 15% of the global population. In this study, as a source of α-amylase used the seeds from Chenopodium quinoa (quinoa). Var. white hualhuas during the germination process, this enzyme was partially purified by ammonium sulfate precipitation to obtain a final specific activity of 35.60U/mg, and a grade of purification of 5 times. The purification was confirmed by SDS-PAGE, where the molecular weight was 44kDa. The enzyme activity was evaluated by Miller method showing maximum activity at pH 7 and 37ºC. The Lineweaver-Burk linearization shows a Km of 16mg/mL and Vmax of 100μM the maltose / min. Therefore, these characterizations meet the prerequisites need for industry. Keywords: Chenopodium quinoa; alpha amylase; germination; partial purification


1985 ◽  
Vol 98 (2) ◽  
pp. 435-448 ◽  
Author(s):  
Scung-Ho KIM ◽  
Saburo HARA ◽  
Sumihiro HASE ◽  
Tokuji IKENAKA ◽  
Hiroko TODA ◽  
...  

1993 ◽  
Vol 101 (4) ◽  
pp. 1401-1402 ◽  
Author(s):  
S. I. Song ◽  
C. H. Kim ◽  
S. J. Baek ◽  
Y. D. Choi

1994 ◽  
Vol 304 (1) ◽  
pp. 301-305 ◽  
Author(s):  
M E Monaco ◽  
M Feldman ◽  
D L Kleinberg

Substantial purification of rat liver phosphatidylinositol (PtdIns) synthase has been achieved by a combination of Hecameg extraction, heat treatment, affinity chromatography and chromatography on PBE-94. The activity chromatographs as a single peak which has an apparent molecular mass between 150 and 200 kDa on Sepharose 4B. When analysed by SDS/PAGE, two major bands are seen. The enzyme activity is correlated with a protein band of 21 kDa. A second band, at 51 kDa, is eluted from a PBE-94 column slightly ahead of the activity. Manganese is an absolute requirement for stabilization of activity in the presence of detergent. The effect of manganese is optimal at 0.5 mM; magnesium at a concentration of 10 mM is only minimally effective. Substrate Kms are 1.3 mM and 9.5 microM for inositol and CDP-diacylglycerol respectively. The activity eluting from the PBE-94 column is purified 5000-fold over the post-mitochondrial supernatant.


2012 ◽  
Vol 47 (No. 10 - 11) ◽  
pp. 283-288 ◽  
Author(s):  
M. Çiftci ◽  
V. Turkoglu ◽  
S. Aldemir

In vitro effects of penicillin, sulbactam, cefazolin, and amikacine on the activity of the enzyme glucose-6-phosphate dehydrogenase in sheep liver were investigated. Glucose 6-phosphate dehydrogenase was purified from sheep liver, using a simple and rapid method. The purification consisted of two steps, preparation of homogenate and 2’, 5’-ADP Sepharose 4B affinity chromatography. As a result of the two consecutive procedures, the enzyme, having the specific activity of 11.76 EU/mg proteins, was purified with a yield of 35.72% and 1.913 fold. In order to control the enzyme purification SDS polyacrylamide gel electrophoresis (SDS-PAGE) was done. SDS-PAGE showed a single band for the enzyme. In addition, I50 values of the antibiotics were determined by plotting activity % vs. antibiotic concentrations. I50 values were 17.71 mM for penicillin, 27.38 mM for sulbactam, 28.88 mM for cefazolin, and 30.59 mM for amikacine.


2019 ◽  
Vol 20 (10) ◽  
pp. 2434 ◽  
Author(s):  
Evgeniya E. Burkova ◽  
Alina E. Grigor’eva ◽  
Dmitrii V. Bulgakov ◽  
Pavel S. Dmitrenok ◽  
Valentin V. Vlassov ◽  
...  

Exosomes are nanovesicles (30–100 nm) containing various RNAs and different proteins. Exosomes are important in intracellular communication, immune function, etc. Exosomes from different sources including placenta were mainly obtained by different types of centrifugation and ultracentrifugations and were reported to contain from a few dozen to thousands of different proteins. First crude exosome preparations from four placentas (normal pregnancy) were obtained here using several standard centrifugations but then were additionally purified by gel filtration on Sepharose 4B. Individual preparations demonstrated different gel filtration profiles showing good or bad separation of exosome peaks from two peaks of impurity proteins and their complexes. According to electron microscopy, exosomes before gel filtration contain vesicles of different size, ring-shaped structures forming by ferritin and clusters of aggregated proteins and their complexes. After filtration through 220 nm filters and gel filtration exosomes display typically for exosome morphology and size (30–100 nm) and do not contain visible protein admixtures. Identification of exosome proteins was carried out by MS and MS/MS MALDI mass spectrometry of proteins’ tryptic hydrolyzates after their SDS-PAGE and 2D electrophoresis. We have obtained unexpected results. Good, purified exosomes contained only 11–13 different proteins: CD9, CD81, CD-63, hemoglobin subunits, interleukin-1 receptor, annexin A1, annexin A2, annexin A5, cytoplasmic actin, alkaline phosphatase, serotransferin, and probably human serum albumin and immunoglobulins. We assume that a possible number of exosome proteins found previously using crude preparations may be very much overestimated. Our data may be important for study of biological functions of pure exosomes.


2006 ◽  
Vol 52 (1) ◽  
pp. 16-23 ◽  
Author(s):  
José de Jesús Serrano-Luna ◽  
Isaac Cervantes-Sandoval ◽  
Jesús Calderón ◽  
Fernando Navarro-García ◽  
Victor Tsutsumi ◽  
...  

Acanthamoeba spp. are free-living amoebae that cause amoebic granulomatous encephalitis, skin lesions, and ocular amoebic keratitis in humans. Several authors have suggested that proteases could play a role in the pathogenesis of these diseases. In the present work, we performed a partial biochemical characterization of proteases in crude extracts of Acanthamoeba spp. and in conditioned medium using 7.5% SDS–PAGE copolymerized with 0.1% m/v gelatin as substrate. We distinguished a total of 17 bands with proteolytic activity distributed in two species of Acanthamoeba. The bands ranged from 30 to 188 kDa in A. castellanii and from 34 to 144 kDa in A. polyphaga. Additionally, we showed that the pattern of protease activity differed in the two species of Acanthamoeba when pH was altered. By using protease inhibitors, we found that the proteolytic activities belonged mostly to the serine protease family and secondly to cysteine proteases and that the proteolytic activities from A. castellanii were higher than those in A. polyphaga. Furthermore, aprotinin was found to in hibit crude extract protease activity on Madin–Darby canine kidney (MDCK) monolayers. These data suggest that protease patterns could be more complex than previously reported.Key words: Acanthamoeba spp., amoebic keratitis, serine proteases, cysteine proteases, cytopathic effect.


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