scholarly journals EFFECT OF ENDOGENOUS PROTEASES ON GELATION OF RED TILE FISH SURIMI

2015 ◽  
Vol 2 (1) ◽  
pp. 42
Author(s):  
Kigen TAKAHASHI ◽  
Emiko OKAZAKI ◽  
Kazufumi OSAKO

Red tile fish Branchiostegus japonicus meat degrades easily. In market, the small- sized fish is traded at a low price. Additionally, the population of red tile fish in the sea around Japan has reduced. Therefore, for effective utilization of small-sized red tile fish, the effect of endogenous proteases on heat-induced gelation of red tile fish surimi was investigated in the research. Fish gels from red tile fish surimi were prepared at different temperatures between 30 – 90 oC. After heating, the samples were cooled in ice water and then mechanical properties and SDS-PAGE patterns were analyzed. Homogenates prepared from the surimi were mixed with protease inhibitor solutions. The mixtures were incubated in water bathes at 40 or 60 oC. After heating, peptide contents in the supernatant and autolytic protein patterns were determined by the Lowry method and SDS-PAGE respectively. The surimi didn’t form heat-induced gels at 30 - 80 oC and SDS–PAGE showed that proteolysis markedly occurred. Addition of 1, 10-phenanthroline, benzamidine or SBTI prevented proteolysis. These results suggest that red tile fish surimi had extremely low gel- forming ability due to endogenous metalloprotease and trypsin-like serine protease. Keywords: Fish products, Gelation, Protease inhibitor, Surimi 

2015 ◽  
Vol 2 (1) ◽  
pp. 39 ◽  
Author(s):  
Toshihiko TAKENAWA ◽  
Kigen TAKAHASHI ◽  
Le-Chang SUN ◽  
Emiko OKAZAKI ◽  
Kazufumi OSAKO

Chicken egg white is generally used in the industry because of its excellent effect to improve physical property of surimi products. The effects of egg white are believed to be derived from its inhibitory activity on surimi endogenous proteases which reduce gel forming ability. However, there are no detailed investigations about inhibitory effects of egg white on the proteases. The effect of ovalbumin (OVA), which is the main protein of egg white, on trypsin activity was investigated in the present study. N-OVA was purified from fresh chicken egg white by ammonium sulfate fractionation and anion-exchange chromatography (Q-sepharose). S-OVA and I-OVA were prepared by heating N-OVA solution at pH10, 55°C for 24h and at 97°C for 30min (pH was not controlled) respectively. To investigate the effect of OVA on the trypsin activity, casein-trypsin mixture solution was heated with or without OVAs at 40°C and the content of peptide generated from casein was measured. SDS-PAGE of casein was also conducted. The amount of peptide from casein was decreased in the presence of OVAs, regardless of OVA types. SDS-PAGE showed all types of OVA inhibited casein degradation. Those suggest that all types of OVA have inhibitory effect on the trypsin activity. Keywords : Surimi, Ovalbumin, Proteases, Egg white 


Author(s):  
Heba A. Mahfouze ◽  
Sherin A. Mahfouze ◽  
Mahmoud E. S. Ottai

Squash or cucurbit (Cucurbita pepo) is one of the famous and important vegetable plants in most world countries. The squash is infected by the critical Zucchini yellow mosaic virus (ZYMV) in Egypt. Though pesticides can protect the plants of pest infections, there are no effective compounds that can be applied as virucides. In this work, the effects of aqueous extracts from Jasmina montana and Artemisia herba-alba on ZYMV infection in the squash plants were examined. In addition, SDS-PAGE protein patterns and enzyme activities were evaluated and induction of resistance by plant elicitors against ZYMV was studied The results observed that using of the aqueous extracts from A. herba-alba or J. montana extracts prior to ZYMV inoculation recorded 100% inhibition of virus infection. Also, complete inhibition was obtained by treatment of A. herba-alba extract with the virus inoculum led to destroy the virus particles due to presence of the effective compounds (terpens, phenolics and the essential oils) in the plant extract. SDS-PAGE protein profiles and enzyme activities were studied in treated and untreated plants. Genomic DNA variation was studied using random amplified polymorphic DNA (RAPD) and Inter-simple sequence repeat (ISSR) loci. The alterations in RAPD and ISSR assays of representative squash plants can be applied to comprehend of induced systemic resistance. These inducers stimulated resistance in the squash plants. Therefore, elicitors should be taken into consideration in the breeding programs for ZYMV control.


2013 ◽  
Vol 8 (10) ◽  
pp. 1934578X1300801 ◽  
Author(s):  
Arvind Dabhade ◽  
Priti Patel ◽  
Ulhas Patil

A thermo-stable, proteinaceous protease inhibitor (LPI) from Lawsonia inermis is reported. The LPI was purified from Lawsonia inermis seeds by subsequent ammonium sulfate precipitation, ion exchange chromatography (DEAE-Cellulose) and gel permeation chromatography (Sephadex-50). The purified protease inhibitor is effective against a wide range of proteases viz. papain, trypsin, pepsin and metallo-protease. The apparent molecular weight of the protease inhibitor is 19 kDa, determined by SDS-PAGE electrophoresis. The protease inhibitor was found to be stable at 70 °C for 30 min. It was also examined for antibacterial activity against Pseudomonas aeruginosa MTCC 7926 and Staphylococcus aureus NCIM 2079; the IC50 values of the purified LPI were 11.4 μg/mL and 16.6 μg/mL respectively.


2004 ◽  
Vol 54 (4) ◽  
pp. 1235-1237 ◽  
Author(s):  
Tom Coenye ◽  
Elke Vanlaere ◽  
Enevold Falsen ◽  
Peter Vandamme

Type and reference strains of Stenotrophomonas maltophilia and Stenotrophomonas africana were compared with each other and with the type strains of other Stenotrophomonas species, using SDS-PAGE of whole-cell proteins, DNA–DNA hybridization and extensive biochemical characterization. S. maltophilia LMG 958T and S. africana LMG 22072T had very similar whole-cell-protein patterns and were also biochemically very similar. A DNA–DNA binding level of 70 % between both type strains confirmed that S. africana and S. maltophilia represent the same taxon. It is concluded that S. africana is a later synonym of S. maltophilia.


Microbiology ◽  
2009 ◽  
Vol 155 (12) ◽  
pp. 3971-3981 ◽  
Author(s):  
Petra Avanzo ◽  
Jerica Sabotič ◽  
Sabina Anžlovar ◽  
Tatjana Popovič ◽  
Adrijana Leonardi ◽  
...  

We have isolated serine protease inhibitors from the basidiomycete Clitocybe nebularis, CnSPIs, using trypsin affinity chromatography. Full-length gene and cDNA sequences were determined for one of them, named cnispin, and the recombinant protein was expressed in Escherichia coli at high yield. The primary structure and biochemical properties of cnispin are very similar to those of the Lentinus edodes serine protease inhibitor, until now the only member of the I66 family of protease inhibitors in the MEROPS classification. Cnispin is highly specific towards trypsin, with K i in the nanomolar range. It also exhibited weaker inhibition of chymotrypsin and very weak inhibition of subtilisin and kallikrein; other proteases were not inhibited. Inhibitory activity against endogenous proteases from C. nebularis revealed a possible regulatory role for CnSPIs in the endogenous proteolytic system. Another possible biological function in defence against predatory insects was indicated by the deleterious effect of CnSPIs on the development of larvae of Drosophila melanogaster. These findings, together with the biochemical and genetic characterization of cnispin, suggest a dual physiological role for this serine protease inhibitor of the I66 MEROPS family.


2008 ◽  
Vol 71 (11) ◽  
pp. 2289-2294 ◽  
Author(s):  
MING-LUN CHIANG ◽  
WEI-LI HO ◽  
ROCH-CHUI YU ◽  
CHENG-CHUN CHOU

Cells of Vibrio parahaemolyticus 690 were subjected either to heat shock at 42°C for 45 min or to ethanol shock in the presence of 5% ethanol for 60 min. The protein profiles of the unstressed and stressed V. parahaemolyticus cells were compared. Additionally, the induction of DnaK- and GroEL-like proteins in the unstressed and stressed cells of V. parahaemolyticus was also examined. Analysis with one-dimensional sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) indicated that three proteins with molecular masses of 93, 77, and 58 kDa were induced by both heat shock and ethanol shock. The protein patterns revealed by two-dimensional electrophoresis were more detailed than those revealed by one-dimensional SDS-PAGE. It was found that heat shock and ethanol shock affected the expression of a total of 28 proteins. Among them, four proteins with molecular masses of 94, 32.1, 26.7, and 25.7 kDa were enhanced by both heat shock and ethanol shock. Furthermore, immunoblot analysis showed the presence of a GroEL-like protein with a molecular mass of 61 kDa in the test organism, with the heat-shocked and ethanol-shocked cells producing a GroEL-like protein in a larger quantity than the unstressed cells. However, DnaK-like protein was not detectable in either the unstressed or the stressed cells.


Animals ◽  
2019 ◽  
Vol 9 (9) ◽  
pp. 626 ◽  
Author(s):  
NingNing Xu ◽  
DiMing Wang ◽  
JianXin Liu

The current study investigated differences of γ-zein protein contents and starch granule characteristics between raw and steam flaked corns and their influences on ruminal starch hydrolyzing bacteria (SHB) attached to corn grain. Two types of raw (Corn1 and Corn2) and their steam-flaked products (SFCorn1 and SFCorn2) were applied to explore physiochemical structures and SHB attachment. SDS-PAGE was conducted to detect γ-zein protein patterns, scanning electron microscope, and small angle X-ray scattering were performed to obtain starch granule morphology, while crystallinity, DQ starch, and DAPI staining were applied to quantify SHB. The steam flaking process destroyed γ-zein proteins and gelatinized starch granules. The median particle size of Corn1 and Corn2 starch granules increased from 17.8 and 18.0 μm to 30.8 and 26.0 μm, but crystallinity decreased from 22.0 and 25.0% to 9.9 and 16.9%, respectively. The percentage of SHB attached to Corn1 residues decreased (p = 0.01) after 4 h incubation, but SHB attached to SFCorn1 residues increased (p = 0.03) after 12 h incubation. Thus, the differences of γ-zein proteins and starch granule physiochemical structures between raw and steam flaked corn played an important role in improving the rate and extent of starch ruminal degradation through altering the process of SHB attached to corn.


Author(s):  
H. Genc ◽  
İ. Emre ◽  
A. Sahin

Background: The seed proteins are used as molecular markers to clarify the systematic problems. Also, electrophoretic techniques are safe tools to identify the seed proteins. In present study, it was used the SDS-PAGE technique to solve the taxonomical problems of eight taxa of genus Lathyrus belong to three sections Orobus, Lathyrostylis and Pratensis according to the globulin B and glutelin. Methods: The seed materials were collected from natural habitats and 0.5 g seed were homogenized and centrifuged based on extraction procedure. In addition, the amounts of seed storage protein subfractions were determined by using protein assay. The electrophoretic analysis were performed according to the 12% SDS-PAGE. The gel documentation system (Bio-Rad, USA) was used to analyse the electrophoretic data and UPGAMA was used to construct the dendogram to show the relationships among the species under focus. Results: Current study showed that the species of section Pratensis were different from species of sections Orobus and Lathyrostylis. The differences among the studied taxa shown clearly and all studied taxa were choosen from the protein patterns. Furthermore, present study demonstrated that L. nivalis has the highest globulin B and glutelin. Results of the present study generally supported the morphological data.


2000 ◽  
Vol 55 (7-8) ◽  
pp. 552-559 ◽  
Author(s):  
Udo Roth ◽  
Annette Friebe ◽  
Heide Schnabl

Abstract Resistance inducing effects of an extract of Lychnis viscaria L. seeds, containing different brassinosteroids (BR), were investigated. Application of aqueous solutions in concentrations from 0.5 to 10 mg/l (dry wt. of extract) resulted in an enhanced resistance of tobacco, cucumber and tomato to viral and fungal pathogens of up to 36% compared with water-treated control plants. No direct anti-fungal effects in mycelium growth assays with Phytophthora infestans could be observed. After treatment and inoculation with powdery mildew a stimulation of different PR-proteins (ca. + 20% for peroxidase, + 30% for chitinase and up to + 68% for β-1,3-glucanase) in cucumber was found. A chitinase in gel-electrophoresisassay showed a stronger induction of a distinct isoform under the same conditions. Time course of peroxidase induction and changes of apoplastic protein patterns revealed by SDS-PAGE indicated an earlier triggering of defence responses after plant-extract treatment and pathogen attack, probably being responsible for the increased resistance. Involvement of the brassinosteroids in the plant extract is discussed to elicit or mediate the activation of defence-mechanisms.


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