Polyacrylamide Gel Electrophoresis Patterns Research Articles

PAMUK ÇEKİRDEĞİ PROTEİN KONSANTRESİNİN KARAKTERİSTİK ÖZELLİKLERİNİN BELİRLENMESİ

The current study focused on characteristic attributes of protein concentrate obtained from oil-free cottonseed. For this, the physicochemical properties namely moisture content, water activity, color, flowability, wettability, and protein solubility of cottonseed protein concentrate (CSPC) were investigated. Water holding capacity (WHC), oil binding capacity (OBC), foaming capacity, foam stability (10 and 30 min), emulsion activity index (EAI) and emulsion stability index (ESI) (10 and 30 min) of proteins were 2.75 g water/g protein, 2.59 g oil/g protein, 29.00%, 93.10% - 69.05%, 6.25 m2/g and 29.27-87.81 min, respectively. Bands regarding CSPC in the 45 kDa molecular weight were detected by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) patterns. Fourier-transform infrared spectroscopy (FTIR) was used to verify the protein-specific structures. Sheet structures in the surface morphology of CSPC were dominant when scanning electron microscopy (SEM) images were investigated. Thermal gravimetric analyzer (TGA) results showed that the protein concentrate exhibited excellent stability to temperature.

In Vitro Infant Digestion of Whey Proteins Isolate-Lactose.

The model in vitro protein digestion technique has received greater attention due to providing significant advantages compared to in vivo experiments. This research employed an in vitro infant digestive static model to examine the protein digestibility of whey proteins isolate-lactose (WPI-Lac). The polyacrylamide gel electrophoresis (PAGE) pattern for alpha-lactalbumin of WPI at 60 min showed no detectable bands, while the alpha-lactalbumin of the WPI-Lac was completely digested after 5 min of gastric digestion. The beta-lactoglobulin of the WPI-Lac was found to be similar to the beta-lactoglobulin of the WPI, being insignificant at pH 3.0. The alpha-lactalbumin of the WPI decreased after 100 min of duodenal digestion at pH 6.5, and the WPI-Lac was completely digested after 60 min. The peptides were identified as ~2 kilodalton (kDa) in conjugated protein, which indicated that the level of degradation of the protein was high, due to the hydrolysis progress. The conjugated protein increased the responsiveness to digestive proteolysis, potentially leading to the release of immunogenic protein by lactose, and to the creation of hypoallergenic protein.

Synchronized Seed Germination and Seedling Growth of Black Cumin

Black cumin (Nigella sativa) is an important medicinal plant in the pharmacological industry. It is cultivated on a commercial scale, but its seeds have a slow, unsynchronized germination rate. Enhancing seed germination is crucial for improving the production of black cumin. The influence of presowing treatments [gibberellic acid (GA3), potassium nitrate, salicylic acid, and stratification at 4 °C] on seed germination was assessed. Seed germination was determined daily for 30 days, and germination parameters, including final germination percentage (FGP), corrected germination rate, number of days to reach 50% of FGP, and seedling length vigor index, were evaluated. Endogenous contents of GA3 and abscisic acid (ABA) in nonstratified and stratified seeds were estimated using high-performance liquid chromatography (HPLC) and seedling growth was determined in 45-day-old seedlings. All presowing treatments tended to boost early germination for the first 10 days compared with the control. Low concentrations of GA3 at 0.25 g·L−1 also increased FGP (80%) compared with the control group (65.55%). Stratification for 4 weeks provided the greatest FGP value at 95.56%, and stratification for 3 weeks proved to be the most effective treatment for optimal seedling growth. Sodium dodecyl sulphate–polyacrylamide gel electrophoresis patterns of stratified seeds revealed the alteration in intensities of 13 bands and the appearance of a new band (180 kDa) indicating a change in the synthesis of proteins during stratification. Moreover, stratification modulated the endogenous GA3 and ABA contents of black cumin seeds, which alleviated the physiological dormancy and resulted in high and synchronized seed germination.

Aerially Applied Zinc Oxide Nanoparticle Affects Reproductive Components and Seed Quality in Fully Grown Bean Plants (Phaseolus vulgaris L.).

The development of reproductive components in plant species is susceptible to environmental stresses. The extensive application of zinc oxide nanoparticles (nZnO) in various agro-industrial processes has jeopardized the performance and functionality of plants. To understand the response of the developmental (gametogenesis and sporogenesis) processes to nanoparticles (NPs) exposure, the aerial application of nZnO and their ionic counterpart of ZnSO4 at four different levels were examined on bean plants (Phaseolus vulgaris) before the flowering stage. To evaluate the mentioned processes, briefly, flowers in multiple sizes were fixed in paraffin, followed by sectioning and optical analysis. The possibility of alteration in reproductive cells was thoroughly analyzed using both light and electron microscopes. Overall, our results revealed the histological defects in male and female reproductive systems of mature plants depend on NPs levels. Furthermore, NPs caused tapetum abnormalities, aberrations in carbohydrate accumulation, and apoptosis. The nZnO induced abnormal alterations right after meiosis and partly hindered the microspore development, leading to infertile pollens. The seed yield and dry weight were reduced to 70 and 82% at 2,000 mg L–1 nZnO foliar exposure, respectively. The sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis pattern showed the increased expression of two proteins at the molecular weight of 28 and 42 kDa at various concentrations of nZnO and ZnSO4. Overall, our results provided novel insights into the negative effect of nano-scaled Zn on the differential mechanism involved in the reproductive stage of the plants compared with salt form.

Changes in physicochemical properties and myofibrillar protein properties in grass carp salted by brining and injection

SummaryThe aim of this study was to investigate the changes in physicochemical properties and myofibrillar protein properties of grass carp meat during brining and brine injection at 4 °C. The time reached equilibrium was 7 h in brining group and 5 h by injection, where the salt content was about 1.76%. The water content, water holding capacity and yield in injection group (86.59%, 9.18% and 110%, respectively) were higher than brining group (84.76%, 11.47%, and 108%, respectively) at equilibrium point significantly (P < 0.05). This was attributed to the more swollen filament lattices and disordered protein structure in injection group (P < 0.05). The myofibrillar protein structure was compared, including sulphydryl content, surface hydrophobicity, solubility, sodium dodecyl sulphate polyacrylamide gel electrophoresis pattern and secondary structure. The injection group presented the better quality of salted fish meat in shorter time.

Wet milling of buckwheat cultivars and some quality properties of the fractions.

The hulled buckwheat cultivars (Aktaş cv. and Güneş cv.) were wet-milled, and then some chemical, yields, colour, functional properties, phenolic compound, antioxidant activity, and pasting, thermal and retrogradation properties of starches were investigated and compared with the wholegrain buckwheat flour (with hull) and buckwheat groat flour (without hull) of the same cultivars. Sodium dodecyl sulphate polyacrylamide gel electrophoresis patterns of flours and protein fractions were examined under reducing and non-reducing conditions. The hull, germ+dietary fibre, protein and starch fractions were collected. The total recovery for Aktaş cv. and Güneş cv. cultivars were 98.1% and 96.1%; total starch yields were 51.6% and 49.7%; pasting temperatures of the starches were found as 83.7 and 85.7°C; and final viscosities of starches were determined as 3.5 and 3.4 Pa·s, respectively. The resistant starch contents of starch fractions of Aktaş cv. ve Güneş cv. were found as 3.28% and 3.62%, respectively. The highest total phenolic compound contents were detected with dimethyl sulphoxide extraction in the germ+dietary fibre fractions. The highest 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity and trolox equivalent antioxidant capacity were found in the hull fraction (as 81.7%) and germ+dietary fibre fraction (as 11.8 mmol/kg) of Aktaş cv. cultivar.

Impact of aqueous ozone mixing on microbiological, quality and physicochemical characteristics of semi-dried buckwheat noodles

The microbiological, microstructural, and physicochemical impact of aqueous ozone mixing (AOM) on semi-dried buckwheat noodles (SBWN) was elucidated in this study. Microbiological measurements declared that AOM reduced the initial total plate count (TPC) of SBWN significantly (P < 0.05) with a prolonged shelf-life of 2 ~ 5 days. Meanwhile, AOM reduced the cooking loss and water absorption along with the enhancement of hardness and tension force. Scanning electron microscopy (SEM) showed that the protein network of surface and cross section became continuous and compact, and wrapped starch granules more effectively. Moreover, an obvious increase in the intensity of the high molecular protein bands was observed in the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) patterns. Furthermore, the sodium dodecyl sulfate extractable protein (SDSEP) under non-reducing condition obviously decreased, and then the SDSEP under reducing condition changed insignificantly (P > 0.05). These results indicated that AOM mainly promoted the protein cross-linking of SBWN by disulfide bond (SS) cross-links.

Microwave-assisted reaction of gelatin with tannic acid: non-thermal effect on the crosslinking process

The reaction of gelatin with tannic acid using microwave heating with simultaneous cooling (MHSC) in comparison with water bath heating was investigated to get some hints on the non-thermal effect of microwave. MHSC showed a better ability to accelerate the reaction rate. It also increased the turbidity, crosslinking degree, and viscosity of the crosslinked gelatin by 91 FTU, 6.8%, and 0.08 respectively, indicating that microwave could improve the properties of the product. Moreover, sodium dodecyl sulfate polyacrylamide gel electrophoresis patterns reflected that the crosslinked gelatin (MHSC) had a higher molecular weight as the gray levels decreased by 9.2% (235–245 kDa), 2.3% (135–145 kDa), and 9.3% (122–132 kDa). More homogeneous aggregations were identified at the crosslinked gelatin by atomic force microscopy. These results proved that microwave has a non-thermal effect in the gelatin crosslinking process, accelerating the crosslinking reaction, and improving the performance of the gelatin product, which may have a good use in industry.

Biochemical changes of Coregonus peled myofibrillar proteins isolates as affected by HRGS oxidation system.

The objective of the study was to research the effect of protein oxidation on the biochemical properties of Coregonus peled muscle proteins. Myofibrillar proteins (MP) prepared from C. peled back muscle was oxidized using a hydroxyl radical-generating system (HRGS: 0.1mM FeCl3 , 0.1mM ascorbic acid (Asc) and 1-20mM H2 O2 ). In the HRGS oxidizing system, the carbonyls, dityrosine content, and the surface hydrophobicity of C. peled MP (p<0.05) increased with the increasing of H2 O2 concentration and oxidation time, while the total sulfhydryl, free amino groups and the Ca-ATPase activity decreased (p<0.05). The sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) pattern reflected the formation of protein polymers and protein degradation. The results indicate that protein oxidation and the increasing levels of biochemical alterations of C. peled MP have influence on the quality of C. peled muscle protein. PRACTICAL APPLICATIONS: Protein oxidation plays a major role in the meat quality deterioration of C. peled, which always leads to a change in protein physical and chemical properties. In this study, the biochemical change of MP isolates as affected by HRGS oxidation system was proposed. Such chemical modification leads to loss of protein amino groups, shift in the isoelectric point of the protein, loss of solubility and functionality. Additionally, protein carbonyls have been found to be potentially toxic to humans, and relevant measurement of dityrosine as those have been found to cause health problems after oral administration. So such modifications are of technological and nutritional relevance.

Functionality of ovalbumin during Chinese steamed bread-making processing

Hen egg is commonly used in some cereal-based food, including cakes and bread. Ovalbumin, one of the major components of egg white protein, can affect the performance of the food product. The interaction between ovalbumin and gluten protein and its effect on property of dough and quality of Chinese steamed bread was investigated in this study. Sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS-PAGE) patterns indicated that ovalbumin was surprisingly not incorporated in glutenins by covalent bond, whereas size-exclusion high-performance liquid chromatography showed that glutenin macropolymer content in glutenins increased slightly. Furthermore, dynamic rheology experiments indicated ovalbumin led to a decrease inG′ andG″ of dough. Based on molecular dynamic simulation and SDS-PAGE results, it was inferred that ovalbumin was not hydrolyzed by endopeptidases during dough fermentation and crosslinked to gluten proteins during steaming. Finally, ovalbumin improved maximum dough height (Hm) during dough development and specific volume of Chinese steamed bread.

Protein denaturation and oxidation in chilled hairtail (Trichiutus haumela) as affected by electrolyzed oxidizing water and chitosan treatment

ABSTRACTThe effect of chitosan (CH) coating combined with electrolyzed oxidizing water (EOW) on microbiological and physicochemical of hairtail (Trichiutus haumela) was evaluated during 15 days of storage at −3°C. Hairtail samples treated by EOW combined with 1.5% (w/v) CH were compared with samples soaked in single material. For storage of 15 days, the thiobarbituric acid value of hairtails increased steadily to 1.79, 1.52, 1.48 mg/100g (p < 0.05) in the EOW, CH, and EOW+CH group, respectively. All of these were significantly lower than that of the control group (2.01 ± 0.04 mg malonaldehyde/100g; p < 0.05). Microbiological results, total volatile basic nitrogen, pH, and peroxide value also revealed that EOW and CH significantly retarded hairtail spoilage. The sodium dodecyl sulfate–polyacrylamide gel electrophoresis pattern of sarcoplasmic proteins revealed CH+EOW could slow down the protein deterioration of fillet. In this study, CH coating combined with EOW effectively extended the shelf life of hairtail to 6–7 days.

External AC Electric Field-Induced Conformational Change in Bovine Serum Albumin

An ac electric field (acEF) application technology has been reported as a principle technique for food preservation. With this method, conformational changes in the protein molecules of food materials may be induced. Conformational changes were experimentally examined using bovine serum albumin (BSA) as a model protein using an acEF technology. The amplitude of acEF was 66.7 kV/m. BSA with acEF (ac-BSA) and BSA without the ac field (n-BSA) were trypsinized under the same conditions. The derived peptides were compared by using sodium dodecyl sulfate polyacrylamide gel electrophoresis patterns. Formation of tryptic peptides was increased in n-BSA, and trypsin digestion was suppressed in ac-BSA. These results indicate that conformational changes in BSA molecules were induced by acEF application.

Effect of Microbial Transglutaminase on Protein Electrophoretic Pattern and Solubility of Wheat Flour and Hull-Less Barley Flour Blends

Background: Barley flour does not contain gluten, so preparation of high-quality bread is not easy. Thus, the incorporation of microbial transglutaminase (MTG) can be attributed as one of the possible strategies to provide crosslinks between wheat and barley proteins to prepare a similar structure to the desired network of gluten. Methods: The MTG, at different levels (0.5, 1, 1.5, and 2%) was added to wheat and hull-less barley in order to evaluate the solubility of available proteins and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) patterns of (20, 35, 50%) dough proteins as well as their fractions by using an electrophoretic system. Also, to enhance the extent of cross-linking in protein matrix by incorporation of MTG, soy protein isolate (SPI) was used (1% MTG+3% SPI, 1.5% MTG+3% SPI). Results: Interactions between wheat and hull-less barley proteins were intensified due to the formation of catalyzed intermolecular covalent bonds by transglutaminase. According to SDS-PAGE results with increment in the levels of MTG, a progressive decrease in the intensity of the bands corresponding to the molecular weight of around 66 KDa was observed. Also by the addition of MTG, the amounts of the soluble proteins (albumin and glubolin) were significantly decreased and the concentrations of insoluble proteins (glutenin and gliadins) were increased. Conclusion: The addition of hull-less barley flour to wheat flour not only provides protein-enriched dough with better amino acid balance but also has influences on dough properties. Keywords: Transglutaminase, electrophoresis, solubility, hull-less barley, wheat flour.

Meloidogyne species infesting tomatoes, cucumbers and eggplants grown in Kahramanmaraş Province, Turkey

In 2009 and 2010, 107 samples of roots and associated soil were collected from vegetable-growing fields in Andirin, Narli, Pazarcik and Turkoglu of Kahramanmaras Province, Turkey. Populations of root-knot nematode were found in tomatoes, eggplants and cucumbers and the species identified using isozymes analysis, mainly esterase resolved by PAGE (Polyacrylamide Gel Electrophoresis) and perineal patterns of nematode females. A single species of root-knot nematode, Meloidogyne incognita was identified from the samples collected. Two esterase phenotypes, one with a single band (I1) and the other with double bands (I2) were found at proportions of 8.5 and 15.8% of total samples, respectively. About 24% of the fields were found to be infested

Comparison of Conventional Washing Processing and pH Shift Processing on Gelation Characteristics of Bighead Carp (Aristichthys nobilis) Muscle Proteins

ABSTRACTIn this study, gelation characteristics of bighead carp (Aristichthys nobilis) protein isolates prepared by pH shift processing were investigated as compared with those of surimi prepared by conventional wash processing. Results showed that the gel from alkali-aided protein isolate exhibited a higher breaking force than that from conventional washed surimi (p < 0.05). However, the gel from conventional washed surimi had higher whiteness (p < 0.05) and lower expressible moisture (p < 0.05). The rheological study showed that protein isolates exhibited different storage modulus and loss tangent patterns from conventional washed surimi during heating. Acid-aided processing could lead to higher denaturation and dissociation for fish muscle myosin and a coarser gel network from the sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) pattern and the scanning electron microscopy (SEM). Overall, there is a potential to apply pH shift processing, especially alkali-aided processing, to extract more proteins from bighead carp muscle for the production of surimi-based food.

Detection of the VP6 gene of group F and G rotaviruses in broiler chicken fecal samples from the Amazon region of Brazil.

The aim of this study was to detect rotavirus F (RVF) and rotavirus G (RVG) in fecal specimens of broiler chickens in Brazil. During 2008 and 2011, a total of 85 fecal samples were collected. The viral genome was extracted, followed by polyacrylamide gel electrophoresis (PAGE), reverse transcription polymerase chain reaction (RT-PCR), and nucleotide sequencing. Samples were screened for rotaviruses by PAGE, and RVF and RVG genome banding patterns were not seen. Using RT-PCR, it was found that 9.4% (8/85) of the pools contained RVF, whereas 10.6% (9/85) contained RVG. The predicted amino acid sequences of RVF and RVG from Brazilian samples were 94.4-95.7% and 96.8-96.9% identical, respectively, to those of prototypes from Germany. The detection of RVF and RVG in this study provides important epidemiological data about the simultaneous circulation of rotaviruses affecting broiler flocks in the Amazon region of Brazil.

Polymerization of wheat gluten and the changes of glutenin macropolymer (GMP) during the production of Chinese steamed bread

Polymerization of gluten and the changes of glutenin macropolymer (GMP) during the production of Chinese steamed bread (CSB) were investigated, providing a theoretical basis to improve and regulate the quality of CSB. Protein extractability and free sulfhydryl (SH) contents increased to some degree during the dough preparation stage, but significantly (P<0.05) decreased during steaming. Remarkable protein aggregates were observed in sodium dodecyl sulfate–polyacrylamide gel electrophoresis (SDS–PAGE) patterns. The microstructure study of the gas cell and the protein network by confocal laser scanning microscopy (CLSM) further revealed the formation of a continuous and three-dimensional gluten network. The loss and recovery of GMP wet weight during dough processing were significant (P<0.05). Glutenin depolymerization negatively correlated with GMP wet weight and the contents of high molecular weight glutenin subunits (HMW-GS) and low molecular weight glutenin subunits (LMW-GS). Gluten polymerization led to a decrease in G′ and G″ of GMP while gluten depolymerization induced a slight recovery in G′ and G″ of GMP.

Characterization of Acid-soluble Collagen from the Skin of Hammerhead Shark (Sphyrna lewini )

The characteristics of the acid-soluble collagen (ASC) from the skin of hammerhead shark (Sphyrna lewini) (ASC-H) were investigated and compared with those of calf skin collagen (CSC). ASC-H with a yield of 4.23 ± 0.54% (based on the wet weight of skins) contained Gly (227 residues/1,000 residues) as the major amino acid and had imino acids of 205 residues/1,000 residues. Amino acid composition, sodium dodecyl sulfate polyacrylamide gel electrophoresis pattern and Fourier transform spectroscopy (FTIR), confirmed that ASC-H was mainly composed of type I collagen. The peptide map of ASC-H was different from that of CSC, suggesting the differences in amino acid sequences and conformation. Td of ASC-H was 16.89C, which was similar to those of cold-water fishes but significantly lower than those of tropical fish species and mammals. ASC-H exhibited high solubility in pH (1-4) and low NaCl concentrations (≤3%). In addition, the lyophilized collagen displayed loose, fibrous and porous ultrastructure. Practical Applications At present, large quantities of by-products, accounting for 50–70% of the original raw material, are generated during the process of aquatic products processing industry. Therefore, optimal use of these by-products is a promising way to protect the environment and produce value-added products to increase the revenue of fish processors. Recently, many scientists have focused their interests on isolation and characterization of collagens extracted from skins of aquatic organisms. However, no information regarding acid-soluble collagen (ASC) from skins of Hammerhead shark (Sphyrna lewini) has been reported. The aim of this study was to isolate and characterize ASC from skin of Hammerhead shark in comparison with type I collagen from calf skin (CSC). Therefore, the collagen extracted from the skin of hammerhead shark could bring considerably economic benefits as a substitute for mammalian collagen.

AN INVESTIGATION ON KERATIN EXTRACTION FROM WOOL AND FEATHER WASTE BY ENZYMATIC HYDROLYSIS

In this study, the possibility of keratin extraction from wool and feather by an enzymatic treatment along with a reducing agent has been investigated. The effects of different parameters, that is, enzyme loading, type of substrate and surfactant, hydrolysis time, and reducing agent concentration, have been examined in order to optimize the enzymatic hydrolysis. The optimal condition for maximum keratin extraction was attained by making use of 1 g/L sodium dodecyl sulfate (an anionic surfactant) and 2.6% (v/v) protease (Savinase), along with 8.6 and 6.4 g/L sodium hydrogen sulfite (a reducing agent) for wool and feathers, respectively, at liquor to fiber ratio of 25 mL/g for 4 hr. The obtained results indicated higher degradation of wool fiber in comparison with feathers, which might be due to the higher hydrophilic nature of the former. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) patterns revealed that the molecular weights of the extracted proteins from wool and feather were lower than those for the untreated fibers. Scanning electron micrographs showed fibers fibrillation and degradation upon enzymatic treatment. Besides, Fourier-transform infrared (FTIR) spectra indicated no evident changes in the chemical structure of the hydrolyzed fibers. However, wool and feather remainders were mostly composed of α-helix and β-sheets conformations, respectively.

Molecular characterization of Rhizoctonia solani isolates the incitant of soybean root rot

Rhizoctonia solani isolates used in this investigation were identified as anastomosis-4 (AG-40), collected from different localities from Assiut governorate in Egypt. Pathogenicity test of seven isolates of R. solani was evaluated on soybean Giza 111 cultivar under greenhouse conditions. All tested isolates were able to infect soybean plants causing root rot with different degrees of severities, isolate No. 1, 2 and 3 showed significantly highest root rot severity, while isolate No. 5 gave the lowest percentage of root rot rating. The sodium dodecyl sulphate polyacrylamide gel electrophoresis patterns were used to compare three isolates of R. solani. There are no variations among R. solani isolates except a few exceptions according to their protein patterns. DNA markers obtained from all isolates showed genetic similarity among different isolates obtained from different geographical regions barring few exceptions. Correlation between DNA patterns of R. solani isolates and their virulence was detected, but no correlation with anastomosis groups (AG).