JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
Ruiyong Wang,Xiaohui Kang,Ruiqiang Wang,Rui Wang,Huanjing Dou,Jing Wu,Chuanjun Song,Junbiao Chang
The interactions between trypsin and caffeine/theophylline were investigated by fluorescence spectroscopy , UV–visible absorption spectroscopy , resonance light scattering and synchronous fluorescence spectroscopy under mimic physiological conditions . The results revealed that the fluorescence quenching of trypsin by caffeine and theophylline was the result of the formed complex of caffeine–trypsin and theophylline–trypsin. The binding constants and thermodynamic parameters at three different temperatures were obtained. The hydrophobic interaction was the predominant intermolecular forces to stabilize the complex. Results showed that caffeine was the stronger quencher and bound to trypsin with higher affinity than theophylline .
研究领域:
生物化学
·
分子药理学
·
药物代谢
·
蛋白质-配体相互作用
·
光谱学
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DOI
高影响因子
JOURNAL OF CHROMATOGRAPHY B-ANALYTICAL TECHNOLOGIES IN THE BIOMEDICAL AND LIFE SCIENCES
·
2014
·
IF 2.694
Guihua Ruan,Meiping Wei,Zhengyi Chen,Rihui Su,Fuyou Du,Yanjie Zheng
A novel large-volume immobilized enzyme reactor (IMER) on small column was prepared with organic–inorganic hybrid silica particles and applied for fast (10 min) and oriented digestion of protein. At first, a thin enzyme support layer was formed in the bottom of the small column by polymerization with α-methacrylic acid and dimethacrylate. After that, amino SiO 2 particles was prepared by the sol–gel method with tetraethoxysilane and 3-aminopropyltriethoxysilane. Subsequently, the amino SiO 2 particles were activated by glutaraldehyde for covalent immobilization of trypsin. Digestive capability of large-volume IMER for proteins was investigated by using bovine serum albumin (BSA), cytochrome c (Cyt- c ) as model proteins. Results showed that although the sequence coverage of the BSA (20%) and Cyt- c (19%) was low, the large-volume IMER could produce peptides with stable specific sequence at 101–105, 156–160, 205–209, 212–218, 229–232, 257–263 and 473–451 of the amino sequence of BSA when digesting 1 mg/mL BSA. Eight of common peptides were observed during each of the ten runs of large-volume IMER. Besides, the IMER could be easily regenerated by reactivating with GA and cross-linking with trypsin after breaking the –C N– bond by 0.01 M HCl. The sequence coverage of BSA from regenerated IMER increased to 25% comparing the non-regenerated IMER (17%). 14 common peptides. accounting for 87.5% of first use of IMER, were produced both with IMER and regenerated IMER. When the IMER was applied for ginkgo albumin digestion, the sequence coverage of two main proteins of ginkgo, ginnacin and legumin, was 56% and 55%, respectively. (Reviewer 2) Above all, the fast and selective digestion property of the large-volume IMER indicated that the regenerative IMER could be tentatively used for the production of potential bioactive peptides and the study of oriented protein digestion.
研究领域:
生物化学
·
分子生物学
·
蛋白质组学
·
酶工程
·
生物材料
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DOI
高影响因子
Waste and Biomass Valorization
·
2024
·Vol. 15
·期 7
·4353-4372
·
IF 2.6
Shankaranarayana Sahana Hosanagara,Gajanana Vijayalaxmi Karki,Chavan Mohan,Chavannavar Suvarna V.,Doddanagappa Shobha
Purpose To analyse phytochemical composition, antioxidant potential, antimicrobial activity and α-amylase, α-glucosidase and xanthine oxidase inhibitory potential of corn silk extracts derived from the Syngenta 5414 corn variety. Methods Corn silk sample was lyophilized and extracted using 80% ethanol, methanol, water or acetone. Phytochemicals were qualitatively screened and bioactive compounds were identified through GCMS. Antimicrobial activities were evaluated using the agar well method for bacteria and fungal biomass method for fungi. The extracts were subjected to evaluation for their antidiabetic activity through α-amylase and α-glucosidase inhibitory assays, while their anti-gout potential was assessed through xanthine oxidase inhibitory assay, encompassing all four solvent extracts in the study. Results Phytochemical screening revealed the presence of phenols, flavonoids, tannins, alkaloids, sterols, protein xanthoproteic, and cardiac glycosides in the extracts. The Folin-Ciocalteu and AlCl 3 assays demonstrated higher yields of phenolics and flavonoids in 80% ethanolic extract. Furthermore, the extracts remarkably scavenged reactive oxygen species like DPPH, ABTS and elicited considerable ferric ion reducing antioxidant power. GC–MS analysis identified 21 compounds in the 80% ethanolic extract, with 1,2,3-Propanetriol-1-acetate, n-Hexadecanoic acid, and 4H-Pyran-4-one,2,3-dihydro-3,5-dihydroxy-6-methyl- as major components. Antimicrobial assays demonstrated the ethanolic (80%) and methanolic extract's remarkable ability to inhibit the growth of Gram-positive bacteria and exhibit anti-fungal properties. The ethanolic (80%) extract exhibited an IC 50 value of 0.70 ± 0.02 and 0.71 ± 0.01 mg against α-amylase and α-glucosidase, respectively, and 33.76 ± 0.43 mg against xanthine oxidase. Conclusion Corn silk exhibits potential as a valuable reservoir of natural bioactive compounds endowed with a wide array of health-promoting properties. Graphical
研究领域:
天然产物化学
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药用植物学
·
生物化学
·
药物代谢
·
微生物学
·
内分泌药理学
·
代谢性疾病
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DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
·
2014
·
IF 2.745
Teng Zhang,Xiao-Ling Xu,Yi-Ning Jin,Jian Wu,Zhi-Kang Xu
Carbon nanotubes are widely applied in electronics, which offers great potential for enhancing the activity of redox enzyme. In this work, polyimide (PI) was blended with multiwalled carbon nanotubes (MWCNTs) and then electrospun into nanofibers for the immobilization of horseradish peroxidase (HRP), a redox enzyme. SEM and TEM were used to characterize the surface morphology of the PI/MWCNTs nanofibers and to analyze the protruding parts induced by the blending of MWCNT. The results indicate that, compared to the virgin PI nanofibers, the blending of MWCNTs increases the retention activity of immobilized HRP from 2.38% to 12.50%. Circular dichroism and UV–vis molecular absorption spectrometry were used to explore the interactions between HRP and MWCNTs . It seems that MWCNTs increase the enzyme activity by the facilitation of electron transfer among the catalytic intermediates “HRP I”, “HRP II” and MWCNTs.
研究领域:
生物化学
·
纳米生物技术
·
酶工程
·
生物材料
·
分析化学
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DOI
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
·
分子生物学
·
蛋白质科学
·
药理学
·
结构生物学
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DOI
高影响因子
RSC Advances
·
2018
·Vol. 8
·期 15
·8026-8038
·
IF 2.936
Shuli Liu,Zhengyang Duan,Changhua He,Xiaojun Xu,Tianguo Li,Yuhuan Li,Xuan Li,Yao Wang,Longqian Xu
Phosphate-modified baker's yeast (PMBY) was prepared, and used as a novel bio-sorbent for the adsorption of Pb2+ from aqueous solution. The influencing factors, absorption isotherms, kinetics, and mechanism were investigated. The scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR) characterization and elemental analysis of PMBY showed that phosphate groups were successfully grafted onto the surface of yeast. The kinetic studies suggested that the adsorption process followed a pseudo-second-order chemisorption. The adsorption process of Pb2+ using PMBY was spontaneous and endothermic. Furthermore, the adsorption of Pb2+ on PMBY can rapidly achieve adsorption equilibrium (in just 3 min), and the maximum adsorption capacity of Pb2+ on PMBY was found to be 92 mg g−1 at 30 °C, which was about 3 times that of the pristine baker's yeast. The suggested mechanism for Pb2+ adsorption on PMBY was based upon ion-exchange, electrostatic interaction and chelation between the phosphate groups and Pb2+. However, compared with the pristine baker's yeast, the higher capacity and rapid adsorption of PMBY for Pb2+ was mainly due to the chelation and electrostatic interactions between the phosphate groups and Pb2+. In addition, the regeneration experiments indicated that the PMBY was easily recovered through desorption in 0.01 M HCl, and that PMBY still exhibited 90.77% of the original adsorption capacity for Pb2+ after five regeneration cycles. These results showed the excellent regeneration capability of PMBY for Pb2+ adsorption. PMBY has shown significant potential for the removal of heavy metals from aqueous solution due to its rapid adsorption, high-capacity and facile preparation.
研究领域:
环境科学
·
生物化学
·
环境污染治理
·
重金属吸附
·
材料科学
✓ 已验证
DOI
高影响因子
BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS
·
2021
·
IF 3.575
Jiantao Chen,Yingkang Dai,Xiangjun Gong,Guangzhao Zhang
The mechanism for protein stabilization or destabilization has long been an open quest. In the present study, we have studied the interactions between amino acids and guanidinium (Gdm + )/ammonium (NH 4 + ) ions by using low field nuclear magnetic resonance (LF-NMR), where Gdm + and NH 4 + are denaturant and stabilizer for proteins, respectively. It shows that Gdm + favors to bind to the thiol group or the hydroxyl group on the side chain but weakly interacts with the α-carboxyl group. In contrast, NH 4 + prefers to bind to the α-carboxyl group but slightly interacts with the thiol group or the hydroxyl group on the side chain of amino acids . 1 HNMR reveals the hydrogen bonding between NH 4 + and the α-carboxyl group, which is not involved in the interactions between Gdm + and cysteine. Our study demonstrates that the strong interactions between the denaturant and the sulfur atom or the disulfide bond promote the direct binding of the denaturant toward proteins, leading to the destabilization.
研究领域:
生物化学
·
分子生物学
·
生物物理化学
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DOI
高影响因子
JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2015
·
IF 2.912
Jianbo Xiao,Petra Högger
Most data of bioactivity from dietary polyphenols have been derived from in vitro cell culture experiments. In this context, little attention is paid to potential artifacts due to chemical instability of these natural antioxidants. An early degradation time (CT10) and half-degradation time (CT50) were defined to characterize the stability of 53 natural antioxidants incubated in Dulbecco’s modified Eagle’s medium (DMEM) at 37 °C. The degree of hydroxylation of flavones and flavonols significantly influenced the stability in order resorcinol-type > catechol-type > pyrogallol-type, with the pyrogallol-type being least stable. In contrast, any glycosylation of polyphenols obviously enhanced their stability. However, the glycosylation was less important compared to the substitution pattern of the nucleus rings. Methoxylation of flavonoids with more than three hydroxyl groups typically improved their stability as did the hydrogenation of the C2═C3 double bond of flavonoids to corresponding flavanoids. There was no significant correlation between the antioxidant potential of polyphenols and their stability. Notably, the polyphenols were clearly more stable in human plasma than in DMEM, which may be caused by polyphenol–protein interactions. It is strongly suggested to carry out stability tests in parallel with cell culture experiments for dietary antioxidants with catechol or pyrogallol structures and pyrogallol-type glycosides in order to avoid artifacts.
研究领域:
食品科学
·
分子生物学
·
生物化学
·
营养生物化学
·
药理学
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DOI
高影响因子
GLYCOCONJUGATE JOURNAL
·
2012
·Vol. 30
·期 6
·577-583
·
IF 2.117
Zhang Wuxia,Mu Haibo,Zhang Amin,Cui Guoting,Chen Hua,Duan Jinyou,Wang Shunchun
The linear non-sulfated glycosaminoglycan, hyaluronic acid (HA), is widely distributed throughout connective, epithelial and neural tissues etc., and is of great importance in tissue hydration, lubrication and cellular function. Along with the age growth, HA will lose its acetyl groups under action of HA N -deacetylase in vivo . However, the biological consequence of this physiological process remains largely unknown. Herein two highly N -deacetylated HAs, dHA-6 and dHA-10 were generated via the NH 2 NH 2 -HIO 3 procedure. Their molecular weights were estimated to be 24 and 16 kDa by high performance gel-permeation chromatography (HPGPC), and the N -deacetylation degrees were 79.4 % and 93 % respectively, as determined by 1 H nuclear magnetic resonance (NMR). The study on moisture-absorption ( Ra ) and -retention ( Rh ) abilities demonstrated that the Ra values of dHAs under conditions of 81 % or 43 % relative humidity, as well as the Rh values of dHAs under dry condition or 43 % relative humidity, were significantly smaller than that of their respective re- N -acetylated products. The decline of moisture-absorption and –retention capacity after HA N -deacetylation were consistent with the appearance of unsolvated amides remained in the N -deacetylated products, as indicated by circular dichroism (CD) spectroscopy. Our findings implied that HA N -deacetylation, in addition to the decrease of HA contents in the elderly persons, might account for manifestations of naturally aged skin, such as laxity, sagging, and wrinkling.
研究领域:
生物化学
·
皮肤科学
·
糖生物学
·
衰老研究
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DOI
高影响因子
BIOESSAYS
·
2004
·Vol. 26
·期 12
·1351-1362
·
IF 6.491
Pierre De Meyts
I present here a personal perspective on more than three decades of research into the structural biology of the insulin–receptor interaction. The solution of the three-dimensional structure of insulin in 1969 provided a detailed understanding of the insulin surfaces involved in self-assembly. In subsequent years, hundreds of insulin analogues were prepared by insulin chemists and molecular biologists, with the goal of relating the structure to the biological function of the molecule. The design of methods for direct receptor-binding studies in the 1970s, and the cloning of the receptor in the mid 1980s, provided the required tools for detailed structure–function studies. In the absence of a full three-dimensional structure of the insulin–receptor complex, I attempt to assemble the existing pieces of the puzzle generated by our and other laboratories, in order to generate a plausible mechanistic model of the insulin–receptor interaction that explains its kinetics and negative cooperativity. BioEssays 26:1351–1362, 2004. © 2004 Wiley Periodicals, Inc.
研究领域:
结构生物学
·
分子内分泌学
·
生物化学
·
受体信号传导
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DOI
高影响因子
JOURNAL OF MATERIALS CHEMISTRY
·
2011
·Vol. 21
·期 40
·16028-16034
·
IF 5.101
Jun Shi,Zhengzheng Zhang,Gefei Li,Shaokui Cao
Alginate/CaCO3 hybrid beads with pH- and thermal-responsive drug release properties were prepared under compressed CO2 using aliphatic poly(urethane-amine)s (PU) as the thermal-responsive component. Polyacrylic acid (PAA) was used as a crystal growth additive to control the structure of the hybrid beads. The hybrid beads were characterized by using scanning electron microscopy, X-ray powder diffraction and thermogravimetric analysis. The interaction between PAA and aliphatic PU contributed to the formation of alginate beads with a compact CaCO3 shell. Indomethacin release behaviour was found to be pH- and thermal-responsive. The release profiles were sustained with CaCO3 microparticles, indicating that the compact CaCO3 shell could hinder the permeability of the encapsulated drug and reduce the drug release effectively. The results suggest that the hybrid alginate beads can be used as “smart” polysaccharide materials for sustained dual-responsive drug delivery.
研究领域:
生物材料
·
药物递送系统
·
高分子科学
·
纳米医学
·
药剂学
·
生物化学
·
组织工程
✓ 已验证
DOI
高影响因子
JOURNAL OF LUMINESCENCE
·
2013
·
IF 2.144
XiaoDan Zeng,Lin Zhu,FuSheng Zhang,LiYun Feng
The interaction of bovine serum with leucomalachite green (LMG) was investigated by spectroscopic methods . LMG was found to quench the intrinsic fluorescence of BSA by dynamic quenching. High quenching constant suggested that LMG can form a complex with BSA. Binding constant and number of binding site were determined. The thermodynamic parameters suggested the main interacting force is hydrophobic forces . The effect of LMG on the conformation of BSA was analyzed by synchronous fluorescence spectroscopy . RLS spectra were also used to reconfirm the formation of complex between BSA and LMG.
研究领域:
生物化学
·
分子生物学
·
光谱学
·
药物代谢
·
蛋白质-配体相互作用
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）