INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2024
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IF 7.7
Bin Jiang,Hongshen Yue,Xinhao Fu,Jiaming Wang,Yu Feng,Dongmei Li,Chunhong Liu,Zhibiao Feng
Prolyl endopeptidase from Aspergillus niger (An-PEP) is an enzyme that recognizes C-terminal peptide bonds of amino acid chains and cleaves them by hydrolysis . An aqueous two-phase system (ATPS) was used to separate An-PEP from fermentation broth. Through single factor experiments, the ATPS containing 16 % ( w/w ) PEG2000 and 15 % ( w/w ) (NH 4 ) 2 SO 4 at pH 6.0 obtained the recovery of 79.74 ± 0.16 % and the purification coefficient of 7.64 ± 0.08. It was then used to produce soy protein isolate peptide (SPIP) by hydrolysis of soy protein isolate (SPI), and SPIP-Ferrous chelate (SPIP-Fe) was prepared with SPIP and Fe 2+ . The chelation conditions were optimized by RSM , as the chelation time was 30 min, chelation temperature was 25 °C, SPIP mass to VC mass was two to one and pH was 6.0. The obtained chelation rate was 82.56 ± 2.30 %. The change in the structures and functional features of SPIP before and after chelation were investigated. The FTIR and UV–Vis results indicated that the chelation of Fe 2+ and SPIP depended mainly on the formation of amide bonds. The fluorescence, SEM and amino acid composition analysis results indicated that Fe 2+ could induce and stabilize the surface conformation and change the amino acid distribution on the surfaces of SPIP. The chelation of SPIP and Fe 2+ resulted in the enhancement of radical scavenging activities and ACE inhibitory activities. This work provided a new perspective for the further development of peptide-Fe chelates for iron supplement.
研究领域:
生物化学
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食品科学
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产品关联
DOI
PubMed
高影响因子
Food Bioscience
·
2025
·
IF 5.9
Liangmin Wei,Jiyang Chu,Lijun Tan,Huanhuan Cai,Lei Wang,Baocai Xu
Nitrites, commonly used as coloring agents in traditional meat processing, can generate carcinogenic N-nitrosamines. This study developed a microbial fermentation-based coloring technology to replace nitrites. A fermented sausage model included five treatments: control; nitrite-added (50 mg/kg); and three treatments inoculated with food-grade probiotics ( Lactiplantibacillus plantarum YR07, Latilactobacillus sakei L48, Latilactobacillus curvatus WQ). Colorimetric analysis showed that on day 7 the YR07 treatment showed significantly higher redness (a* 9.17 ± 0.10) than control (7.38 ± 0.10), L48 (7.52 ± 0.35) and WQ (6.76 ± 0.14) treatments ( p < 0.05), approaching the nitrite-treated treatment (10.55 ± 0.05). UV-Vis spectroscopy confirmed characteristic nitrosylheme in nitrite-treated sausages, whereas zinc protoporphyrin (ZnPP) dominated probiotic-inoculated treatments. Fluorescence spectroscopy further demonstrated sustained highest intensity in YR07 during processing. ZnPP content on day 7, with the YR07 treatment showing significantly higher levels (5.16 ± 0.09 mg/kg) compared to the control (1.98 ± 0.04 mg/kg) and nitrite-treated treatments (0.50 ± 0.03 mg/kg) ( p < 0.05). Ferrochelatase activity in YR07-inoculated sausages (134.54 ± 2.96 U/g) significantly exceeded ( p < 0.05) both the control (102.01 ± 1.09 U/g) and nitrite-treated treatments (9.75 ± 0.72 U/g), demonstrating nitrite's inhibitory effect on the enzyme. HPLC analysis on day 7 showed that YR07-inoculated (13.32 ± 1.36 mg/kg) and nitrite-treated sausages (10.53 ± 49 mg/kg) contained less heme than the control (19.65 ± 0.31 mg/kg), suggesting heme may serve as substrate for ZnPP biosynthesis. This study not only provides a feasible microbial alternative to nitrite but also elucidates the potential mechanism of ZnPP formation.
研究领域:
食品科学
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微生物学
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生物技术
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肉类加工
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生物化学
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产品关联
DOI
高影响因子
PHOTOCHEMISTRY AND PHOTOBIOLOGY
·
2018
·Vol. 95
·期 4
·1045-1051
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IF 2.214
Xian Zhang,Longfei Chen,Lvfen Gao,Xuesong Gao,Nan Li,Yuwei Song,Xinke Huang,Shaoqiang Lin,Xiaoyu Wang
Comparison of the fluorescence intensity caused by the accumulation of PpIX in endometrial cancer xenografts in nude mice after low-dose 5-Aminolevulinic acid (ALA) injection combined with siRNA transfection was mediated by ultrasound microbubbles and polyethyleneimine (PEI) to explore the feasibility of the ultrasound microbubble technique as transfection agents. Knockdown of ferrochelatase (FECH) in human endometrial cancer xenografts in nude mice was performed by transfection with FECH-siRNA mediated by PEI and ultrasound microbubbles alone or in combination; then, low-dose ALA was injected. Subsequently, an in vivo animal imaging system was employed to detect the fluorescence intensity in xenografts. Red fluorescence was observed in xenografts given more than 6.25 mg kg −1 of ALA. When the dose of ALA was greater than 50 mg kg −1 , there was a significant difference in the fluorescence between tumor and other tissues. After the nude mice were transfected with siRNA and treated with low-dose ALA (1.0 mg kg −1 ), apparent PpIX fluorescence of the xenografts was observed, and the fluorescence intensity was PEI+ ultrasound microbubbles > PEI > ultrasound microbubbles. Ultrasound microbubbles in combination with PEI could generate a higher fluorescence intensity of PpIX than that obtained with ultrasound microbubbles or PEI alone, and ultrasound microbubbles could wholly or partially replace PEI under certain conditions.
研究领域:
肿瘤学
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分子生物学
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基因治疗
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癌症研究
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DOI
PubMed
高影响因子
FOOD CHEMISTRY
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2021
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IF 7.514
Yijun Zhang,Xiangjun Ding,Meiqing Li
Mung bean protein was enzymatically hydrolyzed with either alcalase, neutral protease, or papain. The mung bean protein hydrolysates (MPH) showed good ability to chelate ferrous ions, and the chelates had high stability in vitro . The hydrolysates prepared by alcalase showed the highest degree of hydrolysis and the highest ferrous chelating rate. Single factor tests showed that the pH and the material ratio had significant effects on ferrous chelating rates. The optimal MPH to FeCl 2 ·4H 2 O material ratio was 8:1 (w/w) and the optimal pH of the reaction was 7.0, which yielded a chelating rate of 96.19 ± 0.94%. The fraction 3 with the highest ferrous chelating activity up to 61.25 ± 1.02 μg/mg was obtained from MPH by affinity chromatography. Meanwhile, the MPH-Fe complex had higher digestive stability than just MPH in both in vitro and acid-alkali tolerance assays. The characterization results showed that ferrous ions mainly combined with the amino, carboxyl, imidazole and other chelating active groups in mung bean peptides to form peptide-iron chelates. Scanning electron microscopy (SEM) analysis showed that mung bean peptide chelated ferrous ions to form polymer particles. These results provided insight into ways to develop functional foods such as iron-fortified cereals.
研究领域:
食品科学
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生物化学
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营养学
✓ 已验证
DOI
PubMed
高影响因子
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