scholarly journals Enzymatic Hydrolysis of Broken Rice Protein: Antioxidant Activities by Chemical and Cellular Antioxidant Methods

2021 ◽  
Vol 8 ◽  
Author(s):  
Likun Ren ◽  
Jing Fan ◽  
Yang Yang ◽  
Yue Xu ◽  
Fenglian Chen ◽  
...  
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Enzymatic Hydrolysis ◽  
Metal Ion ◽  
Sodium Dodecyl ◽  
Antioxidant Properties ◽  
Length Distribution ◽  
Cell Aging ◽  
Rice Protein ◽  
Broken Rice

Excessive reactive oxygen species (ROS) is an important cause of aging, and supplementing antioxidants through diet is one of the important ways to delay aging. Some studies have confirmed that rice protease hydrolysate has antioxidant activity, but was rarely been investigated on cells. Thus, commercial enzymes, alkaline enzyme, neutral enzyme, pepsin, chymotrypsin, and trypsin were selected to hydrolyze broken rice protein (BRP) to obtain the corresponding hydrolysates, which were A-broken rice protein hydrolysate (BRPH), N-BRPH, P-BRPH, C-BRPH, and T-BRPH, respectively. Then the antioxidant properties of BRPHs were evaluated by different chemical and cellular antioxidation. Molecular weight, peptide length distribution, and amino acid sequence were detected to insight into the antioxidant properties. Among BRPHs, the A-BRPH displayed the strongest hydroxyl radical scavenging activity (IC50 = 1.159 mg/ml) and metal ion-chelating activities (IC50 = 0.391 mg/ml). Furthermore, cellular antioxidation confirmed that A-BRPH significantly increased cell viability and inhibited the intracellular ROS release in both aging cells and cell-aging processes. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) results revealed that peptides with molecular weight <14.5 KDa were produced by enzymatic hydrolysis. Additionally, A-BRPH rich in low molecular weight (<3 kDa) and short-length peptides with some specific amino acids, such as aromatic and hydrophobic amino acids, contributes to the antioxidant properties. This study provided theoretical to the utilization of broken rice and confirmed that A-BRPH could be used in new anti-aging food and health products for human consumption.

Calcium-binding proteins in a vorticellid contractile organelle

1975 ◽  
Vol 19 (1) ◽  
pp. 203-213
Author(s):  
W.B. Amos ◽  
L.M. Routledge ◽  
F.F. Yew
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Calcium Binding ◽  
Binding Proteins ◽  
Sodium Dodecyl ◽  
Aromatic Amino Acids ◽  
Calcium Binding Proteins ◽  
Polyacrylamide Gels ◽  
Protein Species ◽  
Low Concentrations

The proteins of the contractile spasmoneme of Zoothamnium have been examined for comparison with other motile systems. Though capable of calcium-induced contraction, glycerinated preparations of the spasmoneme contain neither actin nor tubulin at levels that can be detected in polyacrylamide gels. Sixty per cent of the protein in sodium dodecyl sulphate gels migrates in a band at a molecular weight of approximately 20,000, consisting largely of 2 similar protein species which are here given the name of spasmins. The amino acid composition of 2 spasmin fractions has been determined by a fluorimetric method. They are rich in Asx, Glx and serine, but have few aromatic amino acids and no cystine or methionine. In calcium-buffered polyacrylamide gels, it was observed that a reduction in the electrophoretic mobility of the spasmins was induced specifically by calcium (but not magnesium) at the same low concentrations as induce contraction. This indicates that the spasmins are calcium-binding proteins which may be involved directly in the calcium-induced contraction of the spasmoneme.

scholarly journals Rabbit Tamm–Horsfall urinary glycoprotein. Chemical composition and subunit structure

1971 ◽  
Vol 122 (5) ◽  
pp. 623-631 ◽  
Author(s):  
Anne M. S. Marr ◽  
A. Neuberger ◽  
Wendy A. Ratcliffe
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Chemical Composition ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Cross Reactivity ◽  
Subunit Structure ◽  
Terminal Amino

1. Tamm–Horsfall glycoprotein from rabbit urine has been isolated and characterized. The homogeneity of the preparation has been established by a variety of procedures including disc gel electrophoresis and ultracentrifugation in aqueous solution, sodium dodecyl sulphate and formic acid. 2. The chemical composition has been determined and a carbohydrate content of approx. 31% was obtained. The relative contents of the amino acids were shown to be very similar to those in human Tamm–Horsfall glycoprotein. A trace of lipid was also detected. 3. Leucine was identified as the only N-terminal amino acid. 4. The subunit structure was investigated in the presence of sodium dodecyl sulphate by gel filtration and disc gel electrophoresis. These studies indicated that the subunit possessed a molecular weight of approx. 84000±6000. A similar value was obtained after reduction and S-alkylation of the glycoprotein indicating that the disulphide bonds were all intrachain. 5. A minimum value for the chemical molecular weight of 85000±6000 was obtained from the number of N-terminal amino acids released by cyanogen bromide cleavage of the glycoprotein. 6. The immunological properties of the glycoprotein were studied. Cross reactivity was demonstrated between human Tamm–Horsfall glycoprotein and a guinea-pig anti-rabbit Tamm–Horsfall antiserum.

scholarly journals Assessment of antioxidant properties of membrane ultrafiltration peptides from mungbean meal protein hydrolysates

2018 ◽  
Author(s):  
Chanikan Sonklin ◽  
Natta Laohakunjit ◽  
Orapin Kerdchoechuen
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
Amino Acid ◽  
Metal Ion ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Scavenging Activity ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power ◽  
Peptide Fractions

Background Bioactive peptides can prevent damage associated with oxidative stress in the human body when consumed regularly. Recently year, peptides have attracted immense interest because of their beneficial functional properties, safety and little or no side effects when used at high concentration. Most antioxidant peptide has small size less than 1 kDa and contains high proportion of hydrophobic amino acid. Particularly Tyr, Leu, Ala, Ile, Val, Lys, Phe, Cys, Met and His exhibited high antioxidant activity. Mungbean protein contain high abundance of protein and hydrophobic amino acid contents, investigating its bioactivity is an important aspect of adding value to this by-product obtained from a growing industry. Therefore, the objectives of this study were to optimize the conditions used to generate MMPH with antioxidant activity form bromelain and to investigate the antioxidant activities of each molecular weight peptide fraction. Methods Response Surface Methodology (RSM) was used for screening the optimal conditions to produce Mungbean meal protein hydrolysate (MMPH). After that optimal MMPH was fractionated using ultrafiltration membranes with different molecular weight (MW) distribution. Crude-MMPH and four peptide fractions were investigated for five antioxidant activities: DPPH scavenging activity, Hydroxyl scavenging activity, Superoxide scavenging activity, Ferric reducing antioxidant power and metal ion chelation activity. Results The optimal condition of crude-MMPH production was 12 % (w/w) of bromelain and hydrolysis time for 12 h. The EC50 of DPPH was the highest for the F4 peptide fraction (MW<1 kDa) at 0.5320 mg/mL. Metal ion chelating activity was generally weak, except for the F4 that had a value of 43.94% at a protein concentration of 5 mg/mL. The F4 also exhibited high hydroxyl and superoxide radical scavenging activities (54 and 65.1%), but poor activity for ferric reducing antioxidant power (0.102 mM Fe2+/mg protein) compared to other peptide fractions and crude-MMPH. Molecular weight and amino acid were the main factors that determined the antioxidant activities of these peptide fractions. Results show that F4 have high antioxidant potentials. Discussion The lowest MW Fraction (less than 1 kDa) showed the highest DPPH activity, superoxide-, hydroxyl-scavenging activity and metal chelation activity. On the other hand, this fraction had poor ferric reducing power. This showed that low molecular weight has an important effect on antioxidant activities. According to the mechanism of the reaction, the potential of antioxidant activity was divided into two main groups: hydrogen atom transfer (HAT) and single electron transfer (SET). Therefore, this finding suggests that the antioxidant mechanism of peptides obtained mungbean could react with many species of free radicals by multiple mechanisms. Mungbean meal peptide can be developed into multiple functional foods which possess both antioxidant properties and aroma/taste.

Preparing oligopeptides from broken rice protein by ultrafiltration-coupled enzymatic hydrolysis

2013 ◽  
Vol 236 (3) ◽  
pp. 419-424 ◽  
Author(s):  
Hongbin Wang ◽  
Jing Wang ◽  
Zhijia Lv ◽  
Yihan Liu ◽  
Fuping Lu
Keyword(s):  
Enzymatic Hydrolysis ◽  
Rice Protein ◽  
Broken Rice

The association of the surface array and the outer membrane of Deinococcus radiodurans

1982 ◽  
Vol 28 (9) ◽  
pp. 1081-1088 ◽  
Author(s):  
B. G. Thompson ◽  
R. G. E. Murray ◽  
J. F. Boyce
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Contact Angle ◽  
Outer Membrane ◽  
Deinococcus Radiodurans ◽  
Guanidine Hydrochloride ◽  
Sodium Dodecyl ◽  
Major Protein ◽  
Wild Type ◽  
Transparent Layer

The hexagonal surface array of Deinococcus radiodurans strain Sark exhibits remarkably strong bonding of its subunits and association with the outer membrane. The array is not dissociated nor is it separated from the outer membrane by reagents that disrupt hydrogen bonds (urea, guanidine hydrochloride), ionic bonds (pH, LiCl, KCl, NaCl), disulphide bonds (β-mercaptoethanol, dithiothreitol), or chelating agents (ethylenediaminetetraacetic acid). Only disruption of the outer membrane with sodium dodecyl sulphate at room temperature separated the two layers. The isolated array was composed of a major protein of 115 000 molecular weight, a minor protein of 108 000 molecular weight, and no other polymers. Their amino acid profile was indicative of a protein, lacking proline, with a high proportion (51.2%, mole/mole) of polar amino acids. The electron-transparent layer between the hexagonal surface array and the outer membrane was still associated with the purified array, suggesting that the electron-transparent "layer" is a component of the protein array and impenetrable to stains so that the reactive groups are inaccessible. The observations suggest that hydrophobic amino acids make up a major domain of the array molecule and that nonspecific hydrophobic interactions are a large component of the forces involved in the tight association of the array within itself and with the underlying outer membrane. The surface of a mutant lacking the hexagonal surface array was compared with the surface of the wild type that possesses the hexagonal surface array using the two-phase droplet system of Schürch et al. (1981. Biochim. Biophys. Acta, 640: 557–571) to estimate the relative surface hydration. The contact angle for the mutant lacking the array was 128.8 ± 0.8 (SEM), n = 39, and the contact angle for the wild type was 92.6 ± 1.4 (SEM), n = 39, indicating that the surface of the outer membrane is relatively more hydrophobic than the outer aspect of the hexagonal surface array.

Cell-free synthesis of cod preproinsulin

1978 ◽  
Vol 56 (8) ◽  
pp. 791-793 ◽  
Author(s):  
Choy L. Hew
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Amino Acid ◽  
Sodium Dodecyl Sulfate ◽  
Gel Electrophoresis ◽  
Wheat Germ ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Insulin Antibodies ◽  
Translation System

Poly(A)-containing ribonucleic acid from cod islet greatly stimulated the incorporation of radioactive amino acids into proteins when assayed in a wheat germ translation system. The translation products were examined by specific immunoprecipitation with guinea pig anti cod insulin antibodies and by extraction with acid–ethanol. These measurements revealed at least a fivefold increase in incorporation of labelled amino acid over the nonprogrammed system. Sodium dodecyl sulfate disc gel electrophoresis and gel filtration chromatography showed a product of molecular weight 12 500, a size considerably larger than cod proinsulin (9000). It is concluded that cod proinsulin is synthesized via a larger precursor, preproinsulin.

scholarly journals Assessment of antioxidant properties of membrane ultrafiltration peptides from mungbean meal protein hydrolysates

2018 ◽  
Author(s):  
Chanikan Sonklin ◽  
Natta Laohakunjit ◽  
Orapin Kerdchoechuen
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
Amino Acid ◽  
Metal Ion ◽  
Antioxidant Activities ◽  
Antioxidant Properties ◽  
Scavenging Activity ◽  
Antioxidant Power ◽  
Ferric Reducing Antioxidant Power ◽  
Peptide Fractions

Background Bioactive peptides can prevent damage associated with oxidative stress in the human body when consumed regularly. Recently year, peptides have attracted immense interest because of their beneficial functional properties, safety and little or no side effects when used at high concentration. Most antioxidant peptide has small size less than 1 kDa and contains high proportion of hydrophobic amino acid. Particularly Tyr, Leu, Ala, Ile, Val, Lys, Phe, Cys, Met and His exhibited high antioxidant activity. Mungbean protein contain high abundance of protein and hydrophobic amino acid contents, investigating its bioactivity is an important aspect of adding value to this by-product obtained from a growing industry. Therefore, the objectives of this study were to optimize the conditions used to generate MMPH with antioxidant activity form bromelain and to investigate the antioxidant activities of each molecular weight peptide fraction. Methods Response Surface Methodology (RSM) was used for screening the optimal conditions to produce Mungbean meal protein hydrolysate (MMPH). After that optimal MMPH was fractionated using ultrafiltration membranes with different molecular weight (MW) distribution. Crude-MMPH and four peptide fractions were investigated for five antioxidant activities: DPPH scavenging activity, Hydroxyl scavenging activity, Superoxide scavenging activity, Ferric reducing antioxidant power and metal ion chelation activity. Results The optimal condition of crude-MMPH production was 12 % (w/w) of bromelain and hydrolysis time for 12 h. The EC50 of DPPH was the highest for the F4 peptide fraction (MW<1 kDa) at 0.5320 mg/mL. Metal ion chelating activity was generally weak, except for the F4 that had a value of 43.94% at a protein concentration of 5 mg/mL. The F4 also exhibited high hydroxyl and superoxide radical scavenging activities (54 and 65.1%), but poor activity for ferric reducing antioxidant power (0.102 mM Fe2+/mg protein) compared to other peptide fractions and crude-MMPH. Molecular weight and amino acid were the main factors that determined the antioxidant activities of these peptide fractions. Results show that F4 have high antioxidant potentials. Discussion The lowest MW Fraction (less than 1 kDa) showed the highest DPPH activity, superoxide-, hydroxyl-scavenging activity and metal chelation activity. On the other hand, this fraction had poor ferric reducing power. This showed that low molecular weight has an important effect on antioxidant activities. According to the mechanism of the reaction, the potential of antioxidant activity was divided into two main groups: hydrogen atom transfer (HAT) and single electron transfer (SET). Therefore, this finding suggests that the antioxidant mechanism of peptides obtained mungbean could react with many species of free radicals by multiple mechanisms. Mungbean meal peptide can be developed into multiple functional foods which possess both antioxidant properties and aroma/taste.

scholarly journals Collagen Hydrolysates for Skin Protection: Oral Administration and Topical Formulation

Antioxidants ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 181 ◽  
Author(s):  
Gabriel Aguirre-Cruz ◽  
Arely León-López ◽  
Verónica Cruz-Gómez ◽  
Rubén Jiménez-Alvarado ◽  
Gabriel Aguirre-Álvarez
Keyword(s):  
Amino Acids ◽  
Molecular Weight ◽  
Oral Administration ◽  
Antioxidant Properties ◽  
Aromatic Amino Acids ◽  
Natural Antioxidants ◽  
Transepidermal Water Loss ◽  
Skin Aging ◽  
Skin Protection ◽  
Topical Formulation

Antioxidants are molecules that delay or inhibit the oxidation of other molecules. Its use significantly increased in recent years in the diet of people. Natural antioxidants are replacing the use of synthetic antioxidant ingredients due to their safety, nutritional, and therapeutic values. Hydrolyzed collagen (HC) is a popular ingredient considered to be an antioxidant. This low molecular weight protein has been widely utilized due to its excellent biocompatibility, easy biodegradability, and weak antigenicity. It is a safe cosmetic biomaterial with good moisturizing properties on the skin. The antioxidant properties of HC are conditioned to the size of the molecule: the lower the molecular weight of peptides, the greater the ability to donate an electron or hydrogen to stabilize radicals. The antioxidant capacity of HC is mostly due to the presence of hydrophobic amino acids in the peptide. The exact mechanism of peptides acting as antioxidants is not clearly known but some aromatic amino acids and histidine are reported to play an important role in the antioxidant activity. Oral ingestion of HC increases the levels of collagen-derived peptides in the blood torrent and improves the skin properties such as elasticity, skin moisture, and transepidermal water loss. Additionally, daily intakes of HC protect the skin against UV melasma, enhances the fibroblast production and extracellular matrix of the skin. HC has been identified as a safe cosmetic ingredient for topical formulations with good moisturizing properties at the stratum corneum layer of the skin. It reduces the effects of skin aging (dryness, laxity, and wrinkles). The use of HC as a principal ingredient in safe formulations for skin protection was reviewed and compared when it is used by topical and/or oral administration.

scholarly journals Effect of Substrate Ratios and the Species of Sugar on the Antioxidant Activity of Glycosylated Products of the Rana Debris Collagen Peptide

2019 ◽  
Vol 78 ◽  
pp. 02006
Author(s):  
Naixin Kang ◽  
Hongxin Song ◽  
Wenyu Zhang ◽  
Jing Zhao ◽  
Menghan Zhang ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Antioxidant Activity ◽  
Enzymatic Hydrolysis ◽  
Environmental Factors ◽  
Maillard Reaction ◽  
Antioxidant Properties ◽  
Raw Material ◽  
Food Research ◽  
Collagen Peptide ◽  
Structural And Functional Properties

The active peptide (molecular weight < 3500 Da) of the enzymatic hydrolysis from Rana debris is used as a raw material of glycosylation. The peptide can be affected by environmental factors, such as pH and temperature, which can destroy structural and functional properties, so the peptide is usually modified by glycosylation. To investigate the effects of glycosylation on the antioxidant activity of Rana Debris Collagen Peptide (RDCP), glycosylated compounds were prepared using different ratios of RDCP and xylose or glucose by the Maillard reaction. The results indicated that the peptide-xylose compound (PXC) showed higher antioxidant activity than the peptide-glucose compound (PGC), and RDCP and xylose heated at a ratio of 1:4 showed good antioxidant properties. The correlation between the glycosylation degree and antioxidant activity was strong. These results indicated that glycosylation can enhance the antioxidant activity of RDCP. Such glycosylated products can be used in the field of food research.

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