scholarly journals Prediction and Identification of Antioxidant Peptides in Potato Protein Hydrolysate

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Juan Wu ◽  
Chao Mao ◽  
Wenli Zhang ◽  
Yu Cheng

Principal component analysis (PCA) was used to cluster the possible amino acid compositions of antioxidant peptides in potato protein hydrolysate (PPH). The antioxidant peptides exhibiting high ABTS+• scavenging capacity were isolated with the procedure of ultrafiltration, gel filtration, and preparative RP-HPLC and identified by UPLC-MS/MS. Phe, Tyr, and His were shown to group together with ABTS+• scavenging capacity in component matrix plot. Three prominent peptides, namely, Phe-Tyr, Tyr-Phe-Glu, and Pro-Pro-His-Tyr-Phe, which matched the sequence of patatin and were made up of Phe and Tyr, were identified. The peptide Tyr-Phe-Glu demonstrated antioxidant activity against Caco-2 cell oxidation induced by H2O2. The results suggested that multivariate analysis could be used to predict the amino acid compositions of antioxidant peptides.

2018 ◽  
Vol 101 (5) ◽  
pp. 1661-1663 ◽  
Author(s):  
Haisheng Zhang ◽  
Jing Xue ◽  
Huanxia Zhao ◽  
Xinshuai Zhao ◽  
Huanhuan Xue ◽  
...  

Abstract Background: The composition and sequence of amino acids have a prominent influence on the antioxidant activities of peptides. Objective: A series of isolation and purification experiments was conducted to explore the amino acid sequence of antioxidant peptides, which led to its antioxidation causes. Methods: The degreased apricot seed kernels were hydrolyzed by compound proteases of alkaline protease and flavor protease (3:2, u/u) to prepare apricot seed kernel hydrolysates (ASKH). ASKH were separated into ASKH-A and ASKH-B by dialysis bag. ASKH-B (MW < 3.5 kDa) was further separated into fractions by Sephadex G-25 and G-15 gel-filtration chromatography. Reversed-phase HPLC (RP-HPLC) was performed to separate fraction B4b into two antioxidant peptides (peptide B4b-4 and B4b-6). Results: The amino acid sequences were Val-Leu-Tyr-Ile-Trp and Ser-Val-Pro-Tyr-Glu, respectively. Conclusions: The results suggested that ASKH antioxidant peptides may have potential utility as healthy ingredients and as food preservatives due to their antioxidant activity. Highlights: Materials with regional characteristics were selected to explore, and hydrolysates were identified by RP-HPLC and matrix-assisted laser desorption ionization-time-of-flight-MS to obtain amino acid sequences.


2014 ◽  
Vol 32 (No. 3) ◽  
pp. 265-272 ◽  
Author(s):  
A. Pęksa ◽  
J. Miedzianka

We determine the effects of the technology of obtaining potato protein preparation and of different variants of enzymatic hydrolysis on the chemical and amino acid compositions of the hydrolysates obtained. Potato protein concentrates obtained through their thermal coagulation in potato juice with calcium chloride, calcium lactate or without salt addition were subjected to enzymatic hydrolysis using two commercial hydrolytic enzymes: endopeptidase (Alcalase) and exopeptidase (Flavourzyme). Chemical (contents of ash, total and coagulable protein) and amino acid compositions of the hydrolysates obtained were determined. On the ground of the findings it was stated that the type of potato protein preparation used and conditions of enzymatic modification influenced on the properties of the hydrolysates obtained. Preparations obtained during the study were characterised by similar chemical and amino acid compositions, whereas the preparation obtained through thermal coagulation with the use of calcium lactate contained insignificantly more protein and essential amino acids. The least liable to enzymatic hydrolysis was the preparation obtained by using calcium chloride, particularly when only endopeptidase was used. The application of endopeptidase enzyme enabled to obtain 60% of proteolysis efficiency and the addition of the second enzyme (exopeptidase) to the protein solution insignificantly increased the proteolysis efficiency (to ca 70%), mainly when the preparation coagulated with the use of calcium chloride was hydrolysed. Proteolysis of the protein preparations obtained with the use of two enzymes was more favourable, particularly due to the quantity of free amino acids in and amino acids composition of the hydrolysates. 


1979 ◽  
Author(s):  
Takashi Morita ◽  
Craig Jackson

Bovine Factor X is eluted in two forms (X1and X2) from anion exchange chromatographic columns. These two forms have indistinguishable amino acid compositions, molecular weights and specific activities. The amino acid sequences containing the γ-carboxyglutamic acid residues have been shown to be identical in X1 and X2(H. Morris, personal communication). An activation peptide is released from the N-terminal region of the heavy chain of Factor X by an activator from Russell’s viper venom. This peptide can be isolated after activation by gel filtration on Sephadex G-100 under nondenaturing conditions. The activation peptides from a mixture of Factors X1 and X2 were separated into two forms by anion-exchange chromatography. The activation peptide (AP1) which eluted first was shown to be derived from Factor X1. while the activation peptiae (AP2) which eluted second was shown to be derived from X2 on the basis of chromatographic separations carried out on Factors X1 and X2 separately. Factor Xa was eluted as a symmetrical single peak. On the basis of these and other data characterizing these products, we conclude that the difference between X1 and X2 are properties of the structures of the activation peptides. (Supported by a grant HL 12820 from the National Heart, Lung and Blood Institute. C.M.J. is an Established Investigator of the American Heart Association).


1995 ◽  
Vol 6 (3) ◽  
pp. 34-37
Author(s):  
Shinobu Fujihara ◽  
Atsuko Kasuga ◽  
Tatsuyuki Sugahara ◽  
Yasuo Aoyagi

1980 ◽  
Vol 187 (3) ◽  
pp. 647-653 ◽  
Author(s):  
K Arakawa ◽  
M Yuki ◽  
M Ikeda

Tryptensin, a vasopressor substance generated from human plasma protein fraction IV-4 by trypsin, has been isolated and the amino acid composition analysed. The procedures used for the isolation were: (a) adsorption of the formed tryptensin on Dowex 50W (X2; NH4+ form); (b) gel filtration through Sephadex G-25; (c) cation-exchange chromatography on CM-cellulose; (d) anion-exchange chromatography on DEAE-cellulose; (e) re-chromatography on CM-cellulose; (f) gel filtration on Bio-Gel P-2; (g) partition chromatography on high-pressure liquid chromatography. The homogeneity of the isolated tryptensin was confirmed by thin-layer chromatography and thin-layer electrophoresis. The amino acid analysis of the hydrolysate suggested the following proportional composition: Asp, 1; Val, 1; Ile, 1; Tyr, 1; Phe, 1; His, 1; Arg, 1; Pro, 1. This composition is identical with that of human angiotensin.


2001 ◽  
Vol 183 (9) ◽  
pp. 2724-2732 ◽  
Author(s):  
Céline Lévesque ◽  
Christian Vadeboncoeur ◽  
Fatiha Chandad ◽  
Michel Frenette

ABSTRACT Streptococcus salivarius, a gram-positive bacterium found in the human oral cavity, expresses flexible peritrichous fimbriae. In this paper, we report purification and partial characterization of S. salivarius fimbriae. Fimbriae were extracted by shearing the cell surface of hyperfimbriated mutant A37 (a spontaneous mutant of S. salivarius ATCC 25975) with glass beads. Preliminary experiments showed that S. salivariusfimbriae did not dissociate when they were incubated at 100°C in the presence of sodium dodecyl sulfate. This characteristic was used to separate them from other cell surface components by successive gel filtration chromatography procedures. Fimbriae with molecular masses ranging from 20 × 106 to 40 × 106Da were purified. Examination of purified fimbriae by electron microscopy revealed the presence of filamentous structures up to 1 μm long and 3 to 4 nm in diameter. Biochemical studies of purified fimbriae and an amino acid sequence analysis of a fimbrial internal peptide revealed that S. salivarius fimbriae were composed of a glycoprotein assembled into a filamentous structure resistant to dissociation. The internal amino acid sequence was composed of a repeated motif of two amino acids alternating with two modified residues: A/X/T-E-Q-M/φ, where X represents a modified amino acid residue and φ represents a blank cycle. Immunolocalization experiments also revealed that the fimbriae were associated with a wheat germ agglutinin-reactive carbohydrate. Immunolabeling experiments with antifimbria polyclonal antibodies showed that antigenically related fimbria-like structures were expressed in two other human oral streptococcal species, Streptococcus mitis andStreptococcus constellatus.


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