Showing 331 results for Protein
Volume 0, Issue 0 (1-2024)
Abstract
Phenylketonuria (PKU) is a genetic disorder necessitating a low-protein and phenylalanine diet. This study aimed to explore the feasibility of producing a low-protein pasta using potato and tapioca starches. The pasta formulation substituted semolina flour with a blend of potato and tapioca starches. Date kernel fiber and xanthan gum were incorporated as prebiotic compounds and texture enhancers, respectively. Physicochemical (moisture, fat, total ash, protein, phenylalanine, cooking loss, cooking time, color indexes, and hardness) and sensory properties (texture, flavor, color, and overall acceptability) were evaluated and compared against the control sample (based on semolina flour). The results demonstrated no significant alteration in moisture and fat content upon substitution, but a significant decrease in ash and protein content (p<0.05). Consequently, phenylalanine levels decreased from 530.58 mg/100 g in the control sample to 24.49-26.60 mg/100 g in the pasta. Replacing flour with starches increased cooking loss, reduced cooking time, and diminished pasta hardness compared to the control (p<0.05). The pasta exhibited higher L* and lower a* and b* values than the control. Sensory evaluation revealed that the pasta containing 35% potato starch and 40% tapioca starch attained the highest scores, indicating its favorable acceptability. Overall, this study suggests that the combination of potato and tapioca starches, along with date kernel fiber and xanthan gum, enables the production of and low-protein pasta suitable for PKU patients.
Fatemeh Ghaderi Ramazi, Abdolreza Jahanbakhshi, Mohammad Soudagar,
Volume 1, Issue 1 (3-2013)
Abstract
This study was carried out to investigate alternative instead of corn gluten meal in diets and the effects of this substitution on blood biochemical and hematological parameters of common carp juvenile. Juvenile's carp with an average 11.5 ± 0.5g, 9 ± 1cm weight and length respectively, were fed with experimental diets for 8 weeks. Diets with 31% crude protein and 3100 kcal kg-1 raw energy alternative levels of 150, 270 and 490 (gr kg-1) and a control diet without corn gluten was made. At the end of the experiment, blood biochemical parameters, including glucose, cholesterol, triglycerides, and hemoglobin, hematocrit, white blood cells (WBC) and red blood cells (RBC) in juveniles fed the experimental diets compared with the control group showed a significant difference (P0.05). Also with replacement value of corn gluten in experimental diets, it was concluded that growth and nutritional factors treatments compared with control group significantly decreased (P
Volume 1, Issue 1 (12-2010)
Abstract
We present a method to predict the flexible and rigid regions based on sequence. We use the free energy of two consequent amino acids to define a factor for distinguishing flexible regions from the rigid ones. Using statistical analysis of this free energy, we assign a normalized number between zero to one hundred which we call it flexibility number. Taking the effects of up to four neighbors of an amino acid, into account, resulted in an efficient prediction of flexible and rigid regions of a protein.
Volume 1, Issue 3 (9-2013)
Abstract
Some Biochemical properties of silver carp surimi prepared by application of acid-alkali aided methods were investigated and compared to that of derived by conventional method. In terms of total protein solubility and recovery, lipid reduction, and total pigment extractability and myoglobin removal there was a significant (P<0.05) difference among the treatments. Acid-aided method showed the most efficiency to recover more proteins (86.2%) in comparison to the alkaline-aided (79.8%) and conventional (76.7%) methods. The lipid reduction percentage was recorded as 43.6%, 58.4% and 72.3% for the conventional method, and acid-alkali aided methods, respectively. In terms of total pigment removal, the conventional method showed higher efficiency (P<0.05) compared to the pH-shifting methods. Conversely, fish protein solubilisation by acid-alkali aided techniques was more efficient (P<0.05) compared to the conventional method of making surimi. In conclusion, pH-shifting techniques were superior in comparison with the conventional method in order to recover more functional proteins and to efficiently reduce the lipid and myoglobin content of resultant fish protein isolate.
Volume 2, Issue 1 (9-2011)
Abstract
Lentiviruses are considered one of the most effective recombinant viruses for gene transfer to mammalian cells and tissues. This study comprises of two essential parts: (1) evaluation of efficiency of protein purification columns in concentration of recombinant lentiviruses, and (2) production of recombinant lentiviruses carrying GDNF coding sequences. In part (1) we co-transfected human embryonic kidney cell line HEK-293T with three lentivirus vectors called transfer (carrying either GFP or Jred), packaging and envelope vectors. After a filtration step, we applied the supernatant from transfected cells to Amicon protein columns for concentration purposes. Centrifugation removed 99% of the supernatant and left behind 500-µl-volume of solution full of virions. We thereby produced a of virus stock. Various dilutions of this stock were added to HEK-293T cells that produced up to 100% infected cells positively expressing transgenes. To examine whether the removed supernatant (overflow) has any trace of infective virus by chance, we also used dilutions of the overflow for infection and observed no sign of eGFP or Jred expression. Given the need for a high-titer virus stock for successful target cell transduction, our results indicate that our filtration method of virus concentration is able to produce high virus titer and is cost-effective and less time consuming than previous methods. In part (2), due to the importance of neurotrophic factor GDNF in differentiation and neuroprotection as well as in therapy of neurodegenerative disorders, we ligated GDNF coding sequence into the lentivirus backbone in the second phase of our study. We applied the same method outlined above to produce high-titer recombinant viruses. Following infection of human astrocytoma cells with this virus stock, we detected 3-fold increase in GDNF mRNA expression using RT-PCR. Lentiviruses carrying GDNF can therefore be generated at high titer using the column method and applied for differentiation and neuroprotection studies.
Volume 2, Issue 1 (3-2016)
Abstract
Background: The over-expression of recombinant proteins in large amount is important for production of therapeutic proteins and structural study. There are several systems for expression of recombinant proteins. One of the most relevant expression systems is Escherichia coli (E. coli). Although this organism has many advantages, most of recombinant proteins expressed in E. coli
hosts form inclusion bodies. For gaining biological activities, these structures should be refolded. Many techniques have been developed for in vitro protein refolding.
Methods:
In this study, a method was designed for inclusion body solubilization and protein refolding. IBs were solubilized in the solution containing 2M urea. This is a mild solubilization method without creating random coil structures in the protein.
Results
: Inclusion bodies undergo mild solubilization with maintain native-like secondary structures. Solubilized proteins were refolded on chromatography column by using native buffer conditions. The results showed the recombinant proteins were purified with high efficiency without aggregation.
Conclusions
: The results suggest that this method is easy, efficient, cheap procedure and usable for obtaining refolded recombinant proteins. In addition, purified protein with the method can be used in diagnosis and/or treatment of diseases.
Volume 2, Issue 3 (9-2013)
Abstract
The carob moth is one of the most devastating pests of pomegranate and some other products. Various pest control measures have been undertaken in order to control this pest but none of them has been successful so far. In the current study the effects of cereal seed proteinaceous extracts including triticale and three wheat cultivars (MV17, Aflak, and Zare) have been studied on α-amylase and protease activity of salivary glands of this insect.Initial screening showed 38, 44, 28 and 76% inhibitory effect for triticlae, MV-17, Aflak, and Zare cereal seed extracts respectively on α-amylase activity. Further studies were performed with Zare wheat cultivar using various concentrations including 13, 6.5, 3.25, 1.625 and 0.8125 µg protein on the enzyme activity and results showed that they inhibited the enzyme activity by 76, 75, 68, 60, and 42%, respectively. Gel assays confirmed the spectrophotometric data i.e the effect of the seed extract on the enzyme was dose dependant. The same trend was observed when seed extracts were tested against proteinase activity. These data suggest that plants produce different proteins with different specificity toward herbivores digestive enzymes some of which could be used for insect control in IPM program.
Volume 2, Issue 3 (7-2016)
Abstract
Background: Leptospirosis has been recognized as an important reemerging infectious disease caused by pathogenic Leptospira spp. A major challenge of this disease is the application of a basic research to improve diagnostic method. Outer membrane proteins of Leptospira are potential candidates that could be useful in diagnosis. Among them the lipL41 is an immunogenic protein which is present only in pathogenic serovars. In order to evaluate genetic conservation of the lipL41 gene, we cloned and sequenced this gene from Leptospira interrogans serovar Canicola.
Materials and Methods: Following the DNA extraction from the serovar, the lipL41 gene was amplified and cloned into pTZ57R/T vector and transformed into the competent E. coli (Top10). Recombinant clones were confirmed by colony PCR and DNA sequencing. The related sequences were then analyzed and compared with the sequences in the Genbank database.
Results: PCR amplification of the lipL41 gene resulted in a 1065 bp PCR product. The PCR based on the lipL41 gene detected all the pathogenic reference serovars of the tested Leptospira spp. It was revealed that in Iran the homology of the lipL41 gene between vaccinal and clinical serovars of Canicola was 100%. It also showed >95.9% homology with other pathogenic serovars in Genbank database, which indicates genetic conservation of this gene.
Conclusion: Because of the conservation of lipL41 gene among different strains of Leptospira and its exclusive presence in leptospira, it was revealed that the cloned gene could be further used as a good candidate for developing diagnostic methods such as ELISA and as positive control in diagnostic PCR.
Volume 2, Issue 4 (12-2013)
Abstract
Citrus tristeza virus (CTV) is among the most destructive pathogens of citrus and causes substantial economic losses in citrus-growing industry worldwide. Considering recent distribution of this pathogen and its capability of transmission by existing aphid vectors in Iran, detection of this virus is enforceable for controlling the damage caused by this pathogen in Iran, as one of the major citrus producing countries. Toward this aim, developing a reliable and sensitive detection method such as enzyme- linked immunosorbant assay (ELISA) would be the first step to detect CTV in large scale screenings of field samples. As the serological method requires great amounts of specific antibody, the consequent preparation of a large scale antigen source for immunization process is necessary. In this study the coat protein gene of CTV (CP25) was amplified by polymerase chain reaction from a cloned CP25 gene in pTZ57R/T and subcloned in pET26b expression vector and named pET-CP25. Two Escherichia coli strains of BL21 and Rosetta Gami (DE3) were transformed by pET-CP25. Expression of recombinant protein was induced by IPTG. The authenticity of recombinant protein was confirmed by western immunoblot analysis using a polyclonal antiserum against CTV particles. The results indicated that CTV coat protein gene was expressed in E.coli. This recombinant protein could be used as a source of antigen for immunization process.
Volume 3, Issue 4 (10-2001)
Abstract
Seed protein profiles of 47 accessions belonging to eleven species and four tribes of
grain legumes were studied, by extracting the total proteins from ten single seeds in each
accession and performing SDS-Polyacrylamide gel electrophoresis. All eleven species were
clearly recognizable from their protein banding patterns, but only Phaseolus vulgaris expressed
high intraspecific variations, followed by Lathyrus sativus. Variation among accessions
of other species was very limited. Cluster analysis, after quantifying the protein
bands, using UPGMA procedure, showed phylogenetic relationships which were in a good
concordance with species classification based on morphological characters. Accessions of
tribe Vicieae formed one cluster (Vicia faba, Lens culinaris, Pisum sativum, Lathyrus sativus
and Vicia ervilia) having nearly equal amounts of three categories of polypeptide:
high, moderate and low molecular weight. The second cluster was a small tribe of Cicereae
(Cicer arietinum accessions) having moderate and low molecular weight polypeptides.
Accessions of Phaseoleae tribe formed the third cluster (Phaseolus vulgaris, Vigna unguiculata
and Vigna radiata), having predominantly high molecular weight polypeptides. Finally,
the more distinct tribe, Aeschynomeneae (Arachis hypogaea accessions), formed a
separate cluster exhibiting a special banding pattern. A unique discrepancy was observed
about Glycine max, which belongs to Phaseoleae but was clustered with Cicereae.
Volume 3, Issue 9 (7-2006)
Abstract
The seeds of ten pomegranate (punica granatum L.) cultivars were analyzed for their physicochemical and oil properties. Also mineral elements such as Zn, Cu, Fe, Mn, Mg, Na and K were determined by ICP atomic emmision spectroscopy. The highest quantities of mineral belonged to Mg, K and Na. Also, the quantities of ash and protein in pomegranate seeds were 1.81-2.35 % and 6.63- 12.95 %, respectively. The average contents of refractometer, unsaponifiable, saponification, iodine, peroxide, acidity, moisture and volatile matter were the ranges 1.50-1.51, 1.16-1.63, 181.3-187.9 mgKOH/g, 165-179.4, 0.3-0.7 meqO2/kg oil, 0.25-0.4 % and 0.10-0.19 %, respectively.
Volume 3, Issue 9 (7-2006)
Abstract
The aim of this research was to study the effects of whey protein concentrate (WPC) and casein hydrolysate (CH) on chemical (pH and titratable acidity), physical (consistency and syneresis) and sensory properties of yogurt containing probiotic bacteria. Reconstituted skim milk at 10% total solids was fortified with 1 and 2% of WPC, CH and blend of them (WPC to CH ratios of 1:1). Reconstituted skim milks were made with 11 and 12% total solids as control. Bioyogurts were prepared with commercial probiotic starter culture (Lactobacillus acidophilus, Bifidobacterium sp., Streptococcus thermophilus and Lactobacillus delbrueckii ssp. bulgaricus). Fermentation was stopped at pH=4.6 and samples stored at 4°C for 21 days. Addition of WPC resulted in the highest pH value and the lowest titratable acidity. Acidity values of supplemented bioyogurt samples increased between 0.12 - 0.19% during 21 days of storage. Mَoreovere syneresis of these yogurts was lower and their consistency was higher than control. Bioyogurts containing WPC had the lowest syneresis and samples containing CH or WPC had the highest consistency. With regards to total acceptability, the best samples were bioyogurts supplemented with WPC and blend of WPC and CH.
Volume 3, Issue 11 (12-2006)
Abstract
The aim of this research was to study the effects of whey protein concentrate (WPC) and casein hydrolysate (CH) on chemical (pH and titratable acidity), physical (consistency and syneresis) and sensory properties of yogurt. Reconstituted skim milk at 10% total solids was fortified with 1 and 2% of WPC, CH and blend of them (WPC to CH ratios of 1:1). For comparison, reconstituted skim milks were made with 11 and 12% total solids as control. Yogurts were prepared with commercial starter culture (Streptococcus thermophilus and Lactobacillus delbrueckii subsp. bulgaricus) and their fermentation proccess were stopped at pH=4.6 and samples stored at 4°C up to 21 days. The lowest pH value was obtained when milk base was supplemented with WPC. pH values of all yogurt samples did not change significantly during 21 days of storage and ~0.18% increase in titratable acidity was observed during storage period. The lowest syneresis was observed in yogurts containing blend of WPC and CH. Moreover, the syneresis values of these yogurts increased slower than other samples during storage. Consistency of fortified yogurts was higher than control yogurt and the consistency values of these samples reduced slower than control sample during 21 days of storage. With regards to total acceptability, the best samples were yogurts supplemented with blend of WPC and CH.
Volume 4, Issue 2 (9-2013)
Abstract
Abstract: ATP sulfurylase (ATPS) is widely distributed in all living organisms. Several different physiological roles have been proposed for ATPS in different species, including sulfate assimilation, sulfate reduction and pyrophosphate recycling. Also, ATP sulfurylase has many different industrial and laboratory applications. The aim of this study was to clone and express the gene that producing the recombinant ATPS protein from an Iranian strain of Geobacillus. After Isolation and identification of Geobacillus kaustophilus strain, DNA genomic was extracted. ATPS gene was amplified from genomic DNA by using a couple of specific primers for interested gene. PCR product of ATPS gene was observed as an 1188bp band on agarose gel. Then the PCR product was purified and cloned into the cloning vector. The ATPS band was sequenced after cloning and result of homology search in the NCBI database confirmed that the cloned gene was ATPS. The ATPS gene was subcloned in expression pET28a plasmid. Expression of recombinant ATPS protein in E. Coli BL21 (DE3) was analyzed using SDS-PAGE gel. Analysis of expressed ATPS protein on SDS-PAGE gel revealed a band at 47.5 KD. Using ATP luminescence method for measuring enzymatic activity of the protein showed that the recombinant protein is active. This is the first study on cloning, expression and enzymatic activity of the ATPS gene from the Geobacillus kaustophilus bacteria.
Maryam Hamedi Shahraki, Saber Khodabandeh, Seyed Jafar Seifabadi, Shahla Hemmati, Sahar Shabani Panbeh Choleh,
Volume 4, Issue 2 (9-2015)
Abstract
The effects of mucal proteins of sea anemone, Stichodactylahaddoni,on different stages of embryonic development of zebra fish (D. rerio) were examined. The sea anemone samples were collected from the intertidal areas of the Hormuz Island (Persian Gulf), and were frozen at -160 °C. Protein and peptide components were extracted by 100% methanol. Following the total protein assessment by ELISA, three concentrations (2.1, 3.7 and 7.4 mg/ml distil water) were prepared. From each concentration, 2 ml was added to the microplates containing 150 zebra fish eggs each, with 2 replications; microplates with normal aquarium water was also used as control group. The eggs were incubated for 72 hrs and the process of embryonic development was observed every 6 to 12 hours. Results showed that the embryonic development was normal in the control group, while the eggs treated with 3.7 and 7.4 mg/ml ofmucal proteins degenerated and blackened in less than 12 hours. Also a delay in the phase of growth in embryonic development was observed in the group with 1.2 mg/ml of protein. Our results showed that the mucal proteins from this sea anemone can affect embryonic development rapidly, causing delayed growth at low concentration, and cell lysis and embryonic degeneration at high concentrations.
, Alireza Alishahi, Bahareh Shabanpour,
Volume 4, Issue 2 (9-2015)
Abstract
The aim of this study, in the first step, was to recover the protein content in wastewater of fish meal factories using chitosan, chitosan nanoparticles and chitosan-aluminum sulphate composition. In the second step, the extracted protein was assessed for its essential amino acids profile. Also, the reduced amount of proteins in the waste water was evaluated by measuring different parameters such as turbidity, pH, COD. Finally, chitosan nanoparticles characteristics were investigated using atomic force microscopy. Results showed that turbidity, COD and soluble protein significantly decreased upon adding different concentrations of chitosan, nanoparticle of chitosan and chitosan-alum (p<0.05). The maximum protein recovery was related to chitosan-alum composition and chitosan nanoparticles with no significant difference between these two treatments. Evaluation of recovered protein in term of amino acids profiles showed that there were essential amino acids such as histidine, lysine, methionine and phenylalanine in protein of fish meal wastewater.
Masoud Rezaei, , ,
Volume 4, Issue 3 (12-2015)
Abstract
The present study was conducted to evaluate the efficacy of the pH-shift process in protein recovery from whole and gutted common kilka and characteristics of the produced gel compared with muscle surimi obtained with the conventional method. Although both acidic and alkaline methods reduced total pigment (TP) in isolates obtained from the whole and gutted fish, the alkaline version was more effective and the lowest amount of TP was observed in the isolate from gutted fish using alkaline version. The last sample also contained the lowest amount of TCA soluble peptide which was significantly lower than the others. Also, gel produced from the isolate recovered form gutted kilka with the alkaline version had significantly higher water holding capacity and gel hardness but it was weaker than the sample obtained with conventional method. The results were supported with higher relative amount of actomyosin and actin in the structure of the gels produced from the gutted fish isolate and surimi from fish muscle, as reflected in SDS-PAGE. Nevertheless, the whiteness of the samples recovered with pH-shift process was quite lower than the muscle surimi which reveals the necessity of more research in this area.
Mohsen Kazemi, Bahareh Shabanpour, Parastoo Pourashouri,
Volume 4, Issue 3 (12-2015)
Abstract
In order to improve the properties of myofibrillar protein-based film from silver carp (Hypophthalmichthys molitrix), nanofibrillated cellulose (NFC) at 3 levels (1, 3 and 5%) was used. Optimum treatment was determined by evaluating the mechanical, physical and optical properties as well as scanning electron microscopy analysis (SEM). Cellulose nanoparticles had no effect on tensile strength but reduced the elasticity of film (p≤0.05). Water vapor barrier property (WVP) and other physical properties of the films were improved by addition of nanofibrillated cellulose at 1%, but decreased at higher concentrations (p≤0.05. Based on SEM, low concentrations of nanoparticles showed more homogeneous dispersion and films had a smoother and better cross-sectional area compared to the higher levels of nanoparticles. Generally, low levels of nanoparticles could be effective to improve the mechanical and physical properties of myofibrillar protein - nanofibrillated cellulose films.
Roghayeh Jafari Taraji, Alireza Alishahi, Seyed Mahdi Ojagh, Abbas Esmaeili Molla,
Volume 4, Issue 3 (12-2015)
Abstract
Protein hydrolysate (PH) from viscera of cultured Siberian sturgeon (Acipenser baerii) was produced. To optimize the production conditions, Response Surface Method (RSM) was employed to examine the effects of three different operating conditions, including time, pH, and enzymatic concentration (Alcalase) on the degree of hydrolysis.The mathematical model showed acceptable fitness of the experimental data as R2 equaled 0.97, which indicated that major part of the variability within the range of values could be explained by the model. The results showed that the highest degree of hydrolysis (58.21%) was related to the treatment which happened at the enzymatic concentration of 2%, 60 minutes time, and pH=8. Treatment under hydrolysis condition (i.e., E/S = 2%, Time = 45 min, and pH = 8.5) had the highest protein content (42.37g/l), which was used as an alternative to commercial peptone medium (Triptic soy broth) to assess the growth of Salmonella typhi bacteria from 0 to 48 hours. Although there was an upward trend in growth rate of S. typhi both in control and No. 15 (Alcalase) treatments, the log growth of control treatment was found to be better than that of Alcalase treatment. However, there existed no significant difference between the two treatments.
Volume 4, Issue 3 (9-2016)
Abstract
MeHg and total mercury concentrations were determined in the muscle tissues of four fish species (Cyprinus carpio, Rutilus frisii, Carassius auratus and Esox lucius) from Anzali wetland (Guilan, Iran). Fish with the highest amount of MeHg was selected to determine the thermodynamic parameters of MeHg extraction. The extractions process was performed in the range of temperatures 331.15 to 367.15 K and at atmospheric pressure. Results show the extraction of MeHg from SH groups of sulfhydryl proteins was an endothermic process with a positive value for entropy and Gibbs free energy changes at the room temperature. Significant difference was found between MeHg content at T=367.15 K and other temperatures. Correlation coefficients results showed that the mercury concentration in muscle tissue was significantly related to the length and weight of fish (p≤0.01). Also, thermodynamic parameters of methylmercury extractions had significant correlation (p≤0.05) with length and weight of the six fish specimen.