International Journal of Peptide Research and Therapeutics
·
2019
·Vol. 26
·期 4
·1991-1999
·
IF 1.219
Cao Mengjie,Lu Kui,Liu Guangbin,Zhao Dongxin,Qi Jianzhao
Affecting the repair function of RAD51 can effectively reverse tumor resistance to chemotherapy and radiotherapy. There is interaction between RAD51 181−200 and BRCA1 846−871 . Using the computer to simulate single mutation of lysine at 862 position of BRCA1 846−871 , six BRCA1 846−871 mutants with significant interaction with RAD51 181−200 were screened out. These mutant peptides were obtained by 9-fluorenylmethyloxycarbonyl (Fmoc) solid-phase peptide synthesis (SPPS) method. All peptides were purified and characterized by liquid chromatography and ESI-MS. In this study, the interaction between RAD51 181−200 and BRCA1 846−871 or mutant peptides was investigated using circular dichroism spectroscopy (CD) and fluorescence spectroscopy. The CD results shown that the secondary structure change of RAD51 181−200 induced by BRCA1 846−871 , BRCA1 846−871 K862F ( F ), BRCA1 846−871 K862G ( G ), BRCA1 846−871 K862E ( E ) and BRCA1 846−871 K862N ( N ) was obvious, which the α-helix content of RAD51 181−200 decreased from 58.3–36.1%, 58.3–36.2%, 58.3–36.4%, 58.3–36.5% and 58.3–36.0%, respectively. While, the addition of BRCA1 846−871 K862P ( P ) and BRCA1 846−871 K862Y ( Y ) hardly changed the α-helix content of RAD51 181−200 . From the fluorescence results, the binding constants of F and Y are 1.00 × 10 5 M −1 and 1.16 × 10 5 M −1 respectively, which were both larger than that of BRCA1 846−871 (9.01 × 10 2 M −1 ). The binding constant of RAD51 181−200 with E (7.45 × 10 3 M −1 ) is slightly higher than that of BRCA1 846−871 . The binding constants of RAD51 181−200 with P (1.24 × 10 3 M −1 ) and N (1.26 × 10 3 M −1 ) are similar to that of BRCA1 846−871 . However, the K b value of G (1.51 × 10 2 M −1 ) is less than that of BRCA1 846−871 . Comparing all spectral data, F is the most significant one interacting with RAD51 181−200 . These findings could provide direction for peptide processing and application.
研究领域:
生物化学
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分子生物学
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肿瘤学
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DOI
高影响因子
FOOD CHEMISTRY
·
2016
·
IF 4.052
Ruipu Xin,Suijian Qi,Chaoxi Zeng,Faez Iqbal Khan,Bo Yang,Yonghua Wang
In this study, the natural deep eutectic solvents (NADESs) based on trehalose and choline chloride have been prepared to enhance the protein thermostability. The results of fourier transform infrared spectroscopy and 1 H nuclear magnetic resonance spectroscopy suggested that there were intensive hydrogen-bonding interactions between trehalose and choline chloride in TCCL3-DES and TCCL3-DES75. The physicochemical properties of TCCL3-DES and TCCL3-DES75 were investigated in the temperature range of 293.15–363.15 K. Our results revealed that the thermostability of lysozyme , a model protein used in this study was dramatically increased in TCCL3-DES75, as evidenced by the disappearance of the denaturing peak from their Differential Scanning Calorimetry (DSC) traces. The results of circular dichroism (CD) experiments further demonstrated that the lysozyme in TCCL3-DES75 unfolded partially at 90 °C and recovered to the initial structure at 20 °C. The study suggests that TCCL3-DES75 might be a potential solvent for stabilizing proteins.
研究领域:
生物化学
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分子生物学
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DOI
PubMed
高影响因子
CHEMOSPHERE
·
2020
·
IF 5.778
Weigang Wang,Yuan Yan,Junjie Wang,Yijing Zhu,Jie Ma,Zhuwu Jiang,Yayi Wang
Extracellular proteins are crucial for the formation and structural maintenance of anammox granules. However, the influence of extracellular polymeric substances (EPS) extraction methods on the secondary structure of extracellular proteins has not been studied fully. In this work, ten EPS extraction methods were applied to anammox granules and compared systematically. The EPS extraction methods were then applied to bovine serum albumin (BSA), a representative of extracellular proteins, to investigate their influence on protein secondary structure by circular dichroism (CD) spectroscopy. The ten EPS extraction methods yielded EPS concentration varying from 5.2 ± 0.1 to 84.8 ± 2.0 mg/g volatile suspended solid (VSS). Tween-20 treatment resulted in the most similar CD spectrum and protein secondary structure to the control. Treatment 0.5% Tween-20 for 4 h was found to be the best condition to preserve protein secondary structure while achieving a high EPS yield (44.4 ± 1.4 mg/g VSS) and limited cell lysis for anammox granules. This study provides an optimized protocol to extract granular EPS when the role of the secondary structure of extracellular proteins in regulating aggregation, adsorption and biofilm formation of microbes is to be elucidated.
研究领域:
环境生物学
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微生物学
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DOI
高影响因子
TENSIDE SURFACTANTS DETERGENTS
·
2021
·Vol. 58
·期 3
·187-194
·
IF 1.049
Yongbo Song,Yulan Niu,Hongyan Zheng,Ying Yao
The interactions between cocopropane bis-guanidinium acetates, tallowpropane bis-guanidinium acetates with bovine serum albumin (BSA) in an aqueous solution were studied by fluorescence and circular dichroic spectroscopy measurements. The aim of the study was to elucidate the influence of the hydrophilic group and the length of the hydrophobic chain of these surfactants on the mechanism of binding to BSA. The results revealed that for both surfactants, at low concentrations, the Stern–Volmer plots had an upward curvature and at high concentrations, the quenching efficiency was decreased with increase in surfactant concentration. Different thermodynamics parameters demonstrated the existence of hydrogen bond and van der Waals force which acting as binding forces. Static quenching was observed among the protein and surfactant. The conformation of BSA was changed at higher surfactant concentrations as shown by synchronous fluorescence and CD spectroscopy. This work reveals the mechanism and binding characteristics between guanidine surfactants and protein, and provided the basis for further applications of surfactants.
研究领域:
生物化学
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分子生物学
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DOI
高影响因子
Food Chemistry-X
·
2025
·
IF 8.2
Yushi Wang,Danli Wang,Mengjiao Xing,Miao Ji,Xiaohuan Jiang,Le Jia,Ling Li,Gongshuai Song,Tinglan Yuan,Jinyan Gong
The inhibitory mechanism of chlorogenic acid (CA) on starch enzymolysis was explored in terms of the effects of on amylases and starch. Molecular docking, circular dichroism and fluorescence spectroscopy were used to study the interaction between CA and amylases. CA changed the secondary structure of amylases, caused fluorescence quenching, and linked to α-amylase and amylglucosidase with binding energy of −12.7 and − 2.1 kcal/mol through hydrogen bonds, electrostatic interactions, and hydrophobic interactions. The rapidly digested starch (RDS) content of the CA-potato/corn starch complexes decreased to 34.72 % and 28.09 %. Enzyme kinetics, degradation kinetics and thermodynamics results indicated the enzymolysis of complexes had lower maximum reaction rate ( V m ), higher Michaelis-Menten constant ( K m ), activation energy ( E a ) and enthalpy variation (Δ H ), reflecting a lower affinity between complexes and amylases . Furthermore, the complexes showed more compact structure. This study helps regulate starch digestion, showing a positive effect on balancing blood glucose level and controlling chronic diseases.
研究领域:
食品化学
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生物化学
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营养科学
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分子生物学
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酶学
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DOI
PubMed
高影响因子
JOURNAL OF MOLECULAR RECOGNITION
·
2016
·Vol. 30
·期 1
·e2566
·
IF 2.091
Hua-jin Zeng,Min Miao,Ran Yang,Ling-bo Qu
In this study, the fibrillation of hen egg-white lysozyme (HEWL) in the absence and presence of different concentrations of silybin was studied by thioflavin T spectroscopy, Congo red binding assays, 8-anilino-1-naphthalenesulfonic acid (ANS) fluorescence assay, circular dichroism, and transmission electron microscopy. The experimental results indicated that not only the fibrillation of HEWL at high temperature (65°C) and low pH (pH = 2.0) could be inhibited effectively by silybin but also the inhibition of HEWL by silybin followed a dose-dependent manner. Molecular docking studies indicated that 2 possible binding modes could be found in the interaction between silybin and HEWL via van der Waals forces and electrostatic forces as well as hydrogen bonding. One of these 2 conformations was directly entered into the cavity of HEWL (binding site I); the other was bound to the surface of HEWL (binding site II). In this way, silybin could not only increase the hydrophobicity of the cavity or the surface of HEWL but also influence the microenvironment of the binding site, which was able to stabilize the structure of HEWL and delay the process of HEWL fibrosis.
研究领域:
生物化学
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分子生物学
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蛋白质科学
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药理学
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结构生物学
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DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE
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2021
·Vol. 56
·期 34
·19283-19295
·
IF 4.22
Qi Shoujing,Zhang Chunyu,Hu Zhengjie,Chen Xuwei
Ionic liquids are becoming widely applied in the extraction/separation of biological molecules. In this study, the solidification of ionic liquid 1-hydroxyethyl-3-vinylimidazole chloride ([HVIM]Cl) was achieved via one-pot free radical copolymerisation with divinylbenzene (DVB) as a cross-linking reagent, giving a mesoporous hydrophilic polymeric ionic liquid (PIL). Mesoporous PIL possesses a large surface area of 328.32 m 2 ·g −1 and a high pore volume of 0.45 cm 3 ·g −1 . Owing to hydrophilic interactions and π–π stacking interactions, the PIL adsorbs ovalbumin (Ova) selectively with a theoretical maximum adsorption capacity of 2468.0 mg·g −1 , and this Ova adsorption fit the Langmuir model well. The captured Ova was efficiently recovered using sodium dodecyl sulphate (0.4%, m·v −1 ) with an elution efficiency of 94.7%. Circular dichroism spectra indicated that the adsorption-elution process caused no conformational changes in Ova, indicating that the prepared PIL is highly biocompatible. The practicability of this mesoporous PIL was well demonstrated by the selective adsorption of Ova from protein mixtures and the efficient isolation of Ova from chicken egg white. Graphical abstract
研究领域:
材料科学
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生物技术
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化学工程
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DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
·
2014
·
IF 2.354
Tianxiang Yin,Miao Qin,Weiguo Shen
The interactions of Gemini surfactants 1-dodecyl- N , N ′-[(1,4-dioxo-1,4-butanediyl)bis(oxy-2,1-ethanediyl)]bis[ N , N ′-dimethylammonium]dibromide (12-su-12) and 1-dodecyl- N , N ′-[((2 E )-1,4-dioxo-2-butene-1,4-diyl)bis(oxy-2,1-ethanediyl)]bis[ N , N ′-dimethylammonium]dibromide (12-fo-12) and the corresponding single-chain surfactant 1-dodecyl- N -[2-(acetyloxy)ethyl]- N , N -dimethyl ammonium bromide (DTAAB) with bovine serum albumin (BSA) were investigated by conductometry, fluorimetry, UV–vis and CD spectrometry, and dynamic light scattering. It was found that the bindings of all three surfactants to BSA were cooperatively driven by electrostatic and hydrophobic interactions. The Gemini surfactants, carrying more charges and hydrophobic tails, showed stronger interactions with BSA than the single-chain surfactant. The presence of the double bond in the spacer of 12-fo-12 enhanced the interaction between the surfactant and BSA and also significantly varied the binding sites as compared to 12-su-12 and DTAAB, which indicated an important role of the property of the spacer in the interaction between the surfactant and BSA.
研究领域:
生物物理化学
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分子生物学
·
药物递送
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蛋白质科学
·
纳米医学
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DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY
·
2016
·
IF 3.035
Xiaoyi Liu,Zhaoxing Ling,Xing Zhou,Farooq Ahmad,Ying Zhou
Butachlor is an effective herbicide to deal with undesired weeds selectively and is used at high levels in Asian countries. However, its interaction and impairment effect on BSA was still not clear. In this study, we investigated the interaction between butachlor and bovine serum albumin (BSA) by multi-spectroscopic methods including UV absorption , circular dichroism (CD) spectra, Fourier transform infrared (FTIR) spectra and fluorescence spectra under physiological conditions (pH = 7.4). The results revealed that there was a static quenching of BSA induced by butachlor stemmed from the formation of complex. Based on thermodynamic data, the interaction of butachlor with BSA was due to happen, and van der Waals force as well as hydrogen bond were the major forces contributed to the interaction. The binding constant K b and number of binding site of butachlor with BSA were 5.158 × 10 5 and 1.372 at 303 K, respectively. The distance r between donor (BSA) and acceptor (butachlor) was 0.113 nm, obtained according to the Förster theory. The results revealed that butachlor induced conformational changes in BSA but the secondary structure of BSA was still retained. In addition, the microenvironment around chromophore residues of BSA, for example, tryptophan , changed as well, resulting from the formation of more hydrogen bonds.
研究领域:
生物化学
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分子药理学
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药物代谢
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环境毒理学
·
蛋白质科学
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DOI
高影响因子
LWT-FOOD SCIENCE AND TECHNOLOGY
·
2021
·
IF 4.952
Kefei Chang,Jingbo Liu,Wei Jiang,Yong Fan,Bo Nan,Sitong Ma,Yan Zhang,Boqun Liu,Ting Zhang
In this study, we investigated the effects of different caffeic acid (CA) concentrations on the ovalbumin structure and foaming properties. When the concentration of CA was 0.18 mg/mL, the surface hydrophobicity of ovalbumin decreased from 705.37 to 542.79, the sulfhydryl content decreased from 4.15 μmol/g to 2.26 μmol/g, and the foaming ability and stability increased by 72% and 71%, respectively. We observed that hydrophobic interactions represented the main binding force between CA and ovalbumin. Using circular dichroism spectroscopy (α-Helix increased from 7.2% to 13.9%) and endogenous fluorescence spectra (Reduction of fluorescence intensity and redshift), it showed that CA affected the secondary and tertiary ovalbumin structure, thus increasing the flexible structure. The increase in particle size Increased from 10.26 nm to 65.97 nm indicated that CA acted as a crosslinking agent between the ovalbumin molecules and increased the viscosity of the system through hydrophobic interactions. Although the increase in ovalbumin aggregation and the decrease in hydrophobicity were not conducive to the foaming properties of ovalbumin solutions, the increase in solubility, absolute potential, and flexible molecular structure contributed to the improvement of the foaming properties. All results showed that CA could improve the foaming properties of ovalbumin, a potential food-grade foaming agent.
研究领域:
食品科学
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生物化学
·
胶体科学
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产品关联
DOI
高影响因子
PROTEIN JOURNAL
·
2024
·
IF 1.9
Yuan Libo,Wang Ke,Fang Yuan,Xu Xiujuan,Chen Yingcun,Zhao Dongxin,Lu Kui
Cecropin A (1–7) is a cationic antimicrobial peptide which contain lots of basic amino acids. To understand the effect of basic amino acids on cecropin A (1–7), analogues CA2, CA3 and CA4 which have more arginine or lysine at the N-terminal or C-terminal were designed and synthesized. The interaction of cecropin A (1–7) and its analogs with DNA was studied using ultraviolet–visible spectroscopy, fluorescence spectroscopy and circular dichroism spectroscopy. Multispectral analysis showed that basic amino acids improved the interaction between the analogues and DNA. The interaction between CA4 and DNA is most pronounced. Fluorescence spectrum indicated that Ksv value of CA4 is 1.19 × 10 5 L mol −1 compared to original peptide cecropin A (1–7) of 3.73 × 10 4 L mol −1 . The results of antimicrobial experiments with cecropin A (1–7) and its analogues showed that basic amino acids enhanced the antimicrobial effect of the analogues. The antimicrobial activity of CA4 against E. coli was eightfold higher than that of cecropin A (1–7). The importance of basic amino acid in peptides is revealed and provides useful information for subsequent studies of antimicrobial peptides. Graphical Abstract
研究领域:
生物化学
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分子生物学
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微生物学
·
光谱学
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产品关联
DOI
PubMed
高影响因子
Foods
·
2024
·Vol. 13
·期 6
·851
·
IF 4.7
Kun Xie,Feng Yang,Xian’e Ren,Yongchun Huang,Fengyan Wei
Effects of different ionic strengths (0.2, 0.4, and 0.6 mol/L) and different hydrodynamic cavitation (HC) treatment times (0, 1, 2, 3, and 4 min) on the conformation and gel properties of tilapia myofibrillar proteins (TMP) were investigated. The results showed that the solubility of TMP was significantly enhanced (p< 0.05) with the increase in NaCl concentration, and the gel characteristics were significantly improved. After HC treatment of TMP, the average particle size was significantly reduced (p< 0.05) and solubility was significantly enhanced (p< 0.05) with the increase in treatment time, the internal hydrophobic groups and reactive sulfhydryl groups were exposed. The intrinsic fluorescence spectra showed the unfolding of the spatial tertiary structure of proteins, and the circular dichroism spectroscopy showed the significant reduction in the content of α-helix in the secondary structure of the proteins (p< 0.05). In addition, the WHC and gel strength of the TMP heat-induced gels were enhanced, which improved the microstructure of the gels, and scanning electron microscopy showed that the gel network of the TMP gels became denser and more homogeneous. Dynamic rheology results showed that HC treatment resulted in a significant increase in the final G’ and G” values of TMP. In conclusion, HC treatment was able to improve the physicochemical structure and gel properties of TMP at different ionic strengths. This study presents a novel processing technique for the quality maintenance aspect of salt-reduced surimi gel products.
研究领域:
食品科学
·
蛋白质化学
·
水生生物学
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DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）