During postmortem storage,fluoride in Antarctic krill can be enriched in the muscle.Trypsin,as the most important digestive enzyme in Antarctic krill with a high activity in low temperature,plays a potential role in t...During postmortem storage,fluoride in Antarctic krill can be enriched in the muscle.Trypsin,as the most important digestive enzyme in Antarctic krill with a high activity in low temperature,plays a potential role in this process.In this study,endogenous trypsin was purified and its properties were investigated.The involvement of trypsin in the generation of free fluoride from Antarctic krill cuticle was explored.Cuticle microstructure before and after hydrolysis was compared with scanning electron microscopy,and the ash samples of the hydrolyzed Antarctic krill cuticle were analyzed with X-ray diffraction,Fourier transform infrared spectroscopy,and electron dispersive spectroscopy,respectively.Mass spectrometry analysis and inhibition tests confirmed that the purified enzyme was endogenous trypsin.Results of the present study indicated that trypsin digestion caused the increases of the concentrations of both fluoride ions and free amino N simultaneously,while the protein coated on the cuticle surface was dissolved too.However,no compositional change was detected in the cuticle inorganic salts.These findings suggest that trypsin triggered free fluoride release from Antarctic krill cuticle.In addition,the kinetics of free fluoride release could be described by the equation C_(W)=(1-0.97^(-0.006t)-0.03e^(0.0558t))×337.53+10.50.The present study improved the understanding of the role of trypsin in free fluoride release from Antarctic krill cuticle,facilitating future studies aimed at reducing the fluoride content in krill protein during Antarctic krill processing.展开更多
Phlorizin(PHL)is a natural compound with strong antioxidant properties mainly found in apples.In this paper,the interaction mechanism of PHL with pepsin and trypsin was comparatively evaluated by computer simulation,f...Phlorizin(PHL)is a natural compound with strong antioxidant properties mainly found in apples.In this paper,the interaction mechanism of PHL with pepsin and trypsin was comparatively evaluated by computer simulation,fluorescence spectra,circular dichroism(CD),and Fourier transform infrared(FT-IR)spectra at a molecular level.Fluorescence spectra showed that PHL quenches the pepsin/trypsin by static quenching.Thermodynamic parameters indicated that PHL binds to pepsin mainly through hydrogen bonds and van der Waals forces,and that of trypsin was electrostatic forces.The ground state complexes PHL and protease have a moderate affinity of 105 L/mol PHL binds more strongly to trypsin than to pepsin.CD and FT-IR spectra results showed that pepsin/trypsin decreased theβ-sheet content and slightly changed its secondary structure upon PHL.These experimental results are mutually verified with the predicted computer-aid simulation results.Upon PHL and trypsin binding,the antioxidant capacity of PHL was elevated.Nevertheless,the antioxidant capacity of PHL was decreased after binding to pepsin.This work elucidates the binding of PHL binding mechanisms to pepsin/trypsin and provides useful information for the digestion of PHL to improve the application of PHL in food processing.展开更多
Trypsin,a novel superoxide scavenger,significantly enhances the storage quality of Hylocereus undatus(H.undatus).To elucidate the preservation mechanism of trypsin on H.undatus,a widely targeted metabolomic analysis,a...Trypsin,a novel superoxide scavenger,significantly enhances the storage quality of Hylocereus undatus(H.undatus).To elucidate the preservation mechanism of trypsin on H.undatus,a widely targeted metabolomic analysis,and transcriptomics analysis were conducted.Firstly,a total of 453 metabolites were identified,with organic acids and their derivatives constituting the largest proportion(25%).Amino acids and their metabolites,prominent among organic acids,were further analyzed.Among them,73 metabolites were associated with amino acids,and 37 exhibited significant differences.The most enriched Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway was arginine biosynthesis(map00220),with polyamine metabolites showing the most pronounced differences,particularly spermine(FC=1.7594).Compared with the control group,4-hydroxy-2-oxoglutaric acid was significantly upregulated(FC=2.117)in the process of spermine biosynthesis.Furthermore,the results of Gene Ontology(GO)and KEGG enrichment analysis of the H.undatus transcriptome profile revealed that trypsin treatment led to 187 differentially expressed genes associated with arginine.Both GO and KEGG analyses exhibited significant enrichment in the spermine biosynthetic process(GO:0006597)(map:00220)within the arginine biosynthesis pathway.Moreover,most enzymes and metabolites within the spermine biosynthesis pathway in H.undatus were upregulated.The results of the PPI network highlighted that ADC,SPDS,and SAMDC,among others,were pivotal proteins involved in trypsin-regulated arginine metabolism and spermine synthesis.This study revealed that trypsin could significantly delay postharvest senescence of H.undatus at room temperature.This effect might be attributed to trypsin triggering the synthesis of 4-hydroxy-2-oxoglutaric acid in the fruit peel,thereby promoting the biosynthesis of spermine and other polyamines.展开更多
目的探究急性缺血性脑卒中(AIS)患者血清间α胰蛋白酶抑制因子重链4(ITIH4)、髓样细胞白血病因子-1(MCL-1)表达与病情程度及预后的关系。方法纳入2019年7月—2022年7月河南科技大学附属黄河医院神经内科诊治AIS患者128例为AIS组。根据...目的探究急性缺血性脑卒中(AIS)患者血清间α胰蛋白酶抑制因子重链4(ITIH4)、髓样细胞白血病因子-1(MCL-1)表达与病情程度及预后的关系。方法纳入2019年7月—2022年7月河南科技大学附属黄河医院神经内科诊治AIS患者128例为AIS组。根据入院时美国国立卫生研究院卒中量表(NIHSS)评分,分为轻度亚组(NIHSS<6分,n=42)、中度亚组(NIHSS 6~<14分,n=52)和重度亚组(NIHSS≥14分,n=34)。根据出院3个月时AIS患者改良Rankins评分,分为预后不良亚组(mRS评分>2分,30例)和预后良好亚组(mRS评分≤2分,98例)。另选取同期医院体检的健康人70例为健康对照组。酶联免疫吸附试验检测血清ITIH4、MCL-1水平。Pearson相关分析血清ITIH4、MCL-1水平与病情程度及预后的相关性;多因素Logistic回归分析影响AIS患者预后的因素;受试者工作特征曲线分析血清ITIH4、MCL-1对AIS患者预后的预测价值。结果AIS组患者血清ITIH4、MCL-1水平显著低于健康对照组(t/P=43.211/<0.001,43.191/<0.001);病情程度越重,AIS患者血清ITIH4/MCL-1水平越低(F/P=107.796/<0.001,297.976/<0.001);预后不良亚组梗死面积、入院24 h NIHSS评分高于预后良好亚组(t/P=9.637/<0.001,9.752/<0.001),血清ITIH4、MCL-1水平及出院3个月简易智能状态量表(MMSE)评分、蒙特利尔认知评估量表(MoCA)评分低于预后良好亚组(t/P=26.723/<0.001,11.709/<0.001,13.674/<0.001,10.782/<0.001);AIS患者血清ITIH4、MCL-1与梗死面积、入院24 h NIHSS评分呈负相关(r/P=-0.705/<0.001,-0.685/<0.001;-0.761/<0.001,-0.619/<0.001),与出院3个月MMSE评分、MoCA评分呈正相关(r/P=0.656/<0.001,0.632/<0.001;0.751/<0.001,0.789/<0.001);出院3个月MMSE评分高、出院3个月MoCA评分高是影响AIS患者预后不良的独立保护因素[0.622(0.446~0.868),0.606(0.427~0.861)],血清ITIH4低、MCL-1低、梗死面积大、入院24 h NIHSS评分高是危险因素[OR(95%CI)=1.467(1.150~1.870),1.415(1.094~1.829),1.605(1.168~2.205),1.765(1.233~2.526)];血清ITIH4、MCL-1及两项联合预测AIS预后不良的AUC分别为0.811、0.835、0.923,两项联合预测AIS预后不良的AUC大于单一指标,差异具有统计学意义(Z=4.258、4.119,P均<0.001)。结论AIS患者血清ITIH4、MCL-1表达下调,两者表达水平与病情严重程度有关,两者联合对AIS患者预后具有较高的预测价值。展开更多
The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation （SSF） with Lactobacillus brevis and Aspergillus oryzae, and to determine the effect of SSF on ph...The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation （SSF） with Lactobacillus brevis and Aspergillus oryzae, and to determine the effect of SSF on phytic acid, crude protein, crude fat, and amino acid profile. Response surface methodology （RSM） with Box-Behnken design was used to optimize SSF. The optimal conditions derived from RSM for L. brevis fermentation were： pH=5. 1; inoculum size=10%; duration=72 h; substrate to water ratio=1.5. The minimum content of trypsin inhibitors was 6.4 mg g^-1 dry matter. The optimal conditions derived from RSM for A. oryzae fermentation were： substrate to water ratio= 0.8 1; inoculum size=4%; duration=120 h. The minimum content of trypsin inhibitors was 1.6 mg g^-1 dry matter. Both L. brevis and A. oryzae decreased trypsin inhibitors dramatically （57.1 and 89.2% respectively）. L. brevis fermentation did not affect phytic acid （0.4%） and crude fat （5.2%） considerably, whereas A. oryzae fermentation degraded phytic acid （34.8%） and crude fat （22.0%） contents to a certain extent. Crude protein content was increased after both fermentation （6.4 and 12.9% for L. brevis and A. oryzae respectively）. Urease activity was reduced greatly （83.3 and 58.3% for L. brevis and A. oryzae respectively）. In conclusion, SSF with A. oryzae and L. brevis reduced trypsin inhibitor content and modified major macronutrients in soybean meal.展开更多
BACKGROUND: Urinary trypsin inhibitor (UTI) inhibits the inflammatory response and protects against ischemia-reperfusion (I/R) injury. The inflammatory response is mediated by nuclear factor-kappa B (NF-kappa B) and i...BACKGROUND: Urinary trypsin inhibitor (UTI) inhibits the inflammatory response and protects against ischemia-reperfusion (I/R) injury. The inflammatory response is mediated by nuclear factor-kappa B (NF-kappa B) and its related target genes and products such as vascular endothelial cell adhesion molecule and CXC chemokines. We aimed to assess the roles of those mediators in a UTI-treated mouse model of hepatic I/R injury. METHODS: Treatment group 1 (UTI given 5 minutes prior to liver ischemia), treatment group 2 (UTI given 5 minutes after the anhepatic phase) and a control group were investigated. Blood and liver samples were obtained and compared at 1, 3, 6 and 24 hours after reperfusion. RESULTS: Attenuation of pathological hepatocellular damage was greater in the treatment groups than in the control group (P < 0.05). Compared with the control group, the UTI treatment groups showed significantly lower serum alanine aminotransferase and aspartate aminotransferase levels, decreased myeloperoxidase activity, and reduced NF-kappa B activation. Also downregulated was the expression of tumor necrosis factor-alpha, cytokine-induced neutrophil chemoattractant, and macrophage inflammatory protein-2 at the mRNA level. P-selectin protein and intercellular adhesion molecule-1 protein expression were also downregulated. In addition, the treatment group I showed a better protective effect against I/R injury than the treatment group 2. CONCLUSIONS: UTI reduces NF-kappa B activation and downregulates the expression of its related mediators, followed by the inhibition of neutrophil aggregation and infiltration in hepatic I/R injury. The protective role of UTI is more effective in prevention than in treatment.展开更多
基金supported by the Guangdong Provincial Key Laboratory of Aquatic Product Processing and Safety(No.GDPKLAPPS2005)the School Level Talent Project of Lingnan Normal University(No.ZL2021009)+2 种基金the Science and Technology Planning Project of Zhanjiang(No.2020A01040)the Study on the Preparation of Active Polypeptide from the Processing Waste of White Shrimp and its Fatigue Resistance(No.2021E05022)the Scientific Research Capacity Improvement Project of the Key Construction Discipline of Guangdong Province(No.2022ZD JS079).
文摘During postmortem storage,fluoride in Antarctic krill can be enriched in the muscle.Trypsin,as the most important digestive enzyme in Antarctic krill with a high activity in low temperature,plays a potential role in this process.In this study,endogenous trypsin was purified and its properties were investigated.The involvement of trypsin in the generation of free fluoride from Antarctic krill cuticle was explored.Cuticle microstructure before and after hydrolysis was compared with scanning electron microscopy,and the ash samples of the hydrolyzed Antarctic krill cuticle were analyzed with X-ray diffraction,Fourier transform infrared spectroscopy,and electron dispersive spectroscopy,respectively.Mass spectrometry analysis and inhibition tests confirmed that the purified enzyme was endogenous trypsin.Results of the present study indicated that trypsin digestion caused the increases of the concentrations of both fluoride ions and free amino N simultaneously,while the protein coated on the cuticle surface was dissolved too.However,no compositional change was detected in the cuticle inorganic salts.These findings suggest that trypsin triggered free fluoride release from Antarctic krill cuticle.In addition,the kinetics of free fluoride release could be described by the equation C_(W)=(1-0.97^(-0.006t)-0.03e^(0.0558t))×337.53+10.50.The present study improved the understanding of the role of trypsin in free fluoride release from Antarctic krill cuticle,facilitating future studies aimed at reducing the fluoride content in krill protein during Antarctic krill processing.
基金supported by the National Natural Science Foundation of China(21808020)the Applied Basic Research Program of Science&Technology Department of Sichuan Province(2018JY0151)。
文摘Phlorizin(PHL)is a natural compound with strong antioxidant properties mainly found in apples.In this paper,the interaction mechanism of PHL with pepsin and trypsin was comparatively evaluated by computer simulation,fluorescence spectra,circular dichroism(CD),and Fourier transform infrared(FT-IR)spectra at a molecular level.Fluorescence spectra showed that PHL quenches the pepsin/trypsin by static quenching.Thermodynamic parameters indicated that PHL binds to pepsin mainly through hydrogen bonds and van der Waals forces,and that of trypsin was electrostatic forces.The ground state complexes PHL and protease have a moderate affinity of 105 L/mol PHL binds more strongly to trypsin than to pepsin.CD and FT-IR spectra results showed that pepsin/trypsin decreased theβ-sheet content and slightly changed its secondary structure upon PHL.These experimental results are mutually verified with the predicted computer-aid simulation results.Upon PHL and trypsin binding,the antioxidant capacity of PHL was elevated.Nevertheless,the antioxidant capacity of PHL was decreased after binding to pepsin.This work elucidates the binding of PHL binding mechanisms to pepsin/trypsin and provides useful information for the digestion of PHL to improve the application of PHL in food processing.
基金the National Key Research and Development Program of China(2017YFC1600802).
文摘Trypsin,a novel superoxide scavenger,significantly enhances the storage quality of Hylocereus undatus(H.undatus).To elucidate the preservation mechanism of trypsin on H.undatus,a widely targeted metabolomic analysis,and transcriptomics analysis were conducted.Firstly,a total of 453 metabolites were identified,with organic acids and their derivatives constituting the largest proportion(25%).Amino acids and their metabolites,prominent among organic acids,were further analyzed.Among them,73 metabolites were associated with amino acids,and 37 exhibited significant differences.The most enriched Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway was arginine biosynthesis(map00220),with polyamine metabolites showing the most pronounced differences,particularly spermine(FC=1.7594).Compared with the control group,4-hydroxy-2-oxoglutaric acid was significantly upregulated(FC=2.117)in the process of spermine biosynthesis.Furthermore,the results of Gene Ontology(GO)and KEGG enrichment analysis of the H.undatus transcriptome profile revealed that trypsin treatment led to 187 differentially expressed genes associated with arginine.Both GO and KEGG analyses exhibited significant enrichment in the spermine biosynthetic process(GO:0006597)(map:00220)within the arginine biosynthesis pathway.Moreover,most enzymes and metabolites within the spermine biosynthesis pathway in H.undatus were upregulated.The results of the PPI network highlighted that ADC,SPDS,and SAMDC,among others,were pivotal proteins involved in trypsin-regulated arginine metabolism and spermine synthesis.This study revealed that trypsin could significantly delay postharvest senescence of H.undatus at room temperature.This effect might be attributed to trypsin triggering the synthesis of 4-hydroxy-2-oxoglutaric acid in the fruit peel,thereby promoting the biosynthesis of spermine and other polyamines.
文摘目的探究急性缺血性脑卒中(AIS)患者血清间α胰蛋白酶抑制因子重链4(ITIH4)、髓样细胞白血病因子-1(MCL-1)表达与病情程度及预后的关系。方法纳入2019年7月—2022年7月河南科技大学附属黄河医院神经内科诊治AIS患者128例为AIS组。根据入院时美国国立卫生研究院卒中量表(NIHSS)评分,分为轻度亚组(NIHSS<6分,n=42)、中度亚组(NIHSS 6~<14分,n=52)和重度亚组(NIHSS≥14分,n=34)。根据出院3个月时AIS患者改良Rankins评分,分为预后不良亚组(mRS评分>2分,30例)和预后良好亚组(mRS评分≤2分,98例)。另选取同期医院体检的健康人70例为健康对照组。酶联免疫吸附试验检测血清ITIH4、MCL-1水平。Pearson相关分析血清ITIH4、MCL-1水平与病情程度及预后的相关性;多因素Logistic回归分析影响AIS患者预后的因素;受试者工作特征曲线分析血清ITIH4、MCL-1对AIS患者预后的预测价值。结果AIS组患者血清ITIH4、MCL-1水平显著低于健康对照组(t/P=43.211/<0.001,43.191/<0.001);病情程度越重,AIS患者血清ITIH4/MCL-1水平越低(F/P=107.796/<0.001,297.976/<0.001);预后不良亚组梗死面积、入院24 h NIHSS评分高于预后良好亚组(t/P=9.637/<0.001,9.752/<0.001),血清ITIH4、MCL-1水平及出院3个月简易智能状态量表(MMSE)评分、蒙特利尔认知评估量表(MoCA)评分低于预后良好亚组(t/P=26.723/<0.001,11.709/<0.001,13.674/<0.001,10.782/<0.001);AIS患者血清ITIH4、MCL-1与梗死面积、入院24 h NIHSS评分呈负相关(r/P=-0.705/<0.001,-0.685/<0.001;-0.761/<0.001,-0.619/<0.001),与出院3个月MMSE评分、MoCA评分呈正相关(r/P=0.656/<0.001,0.632/<0.001;0.751/<0.001,0.789/<0.001);出院3个月MMSE评分高、出院3个月MoCA评分高是影响AIS患者预后不良的独立保护因素[0.622(0.446~0.868),0.606(0.427~0.861)],血清ITIH4低、MCL-1低、梗死面积大、入院24 h NIHSS评分高是危险因素[OR(95%CI)=1.467(1.150~1.870),1.415(1.094~1.829),1.605(1.168~2.205),1.765(1.233~2.526)];血清ITIH4、MCL-1及两项联合预测AIS预后不良的AUC分别为0.811、0.835、0.923,两项联合预测AIS预后不良的AUC大于单一指标,差异具有统计学意义(Z=4.258、4.119,P均<0.001)。结论AIS患者血清ITIH4、MCL-1表达下调,两者表达水平与病情严重程度有关,两者联合对AIS患者预后具有较高的预测价值。
基金supported by a research project of the Science and Technology Key Group in Zhejiang Provincethe research projects from the Science and Technology Department of Zhejiang Province,China (2009C12068)
文摘The aim of the present study was to optimize trypsin inhibitor degradation in soybean meal by solid-state fermentation （SSF） with Lactobacillus brevis and Aspergillus oryzae, and to determine the effect of SSF on phytic acid, crude protein, crude fat, and amino acid profile. Response surface methodology （RSM） with Box-Behnken design was used to optimize SSF. The optimal conditions derived from RSM for L. brevis fermentation were： pH=5. 1; inoculum size=10%; duration=72 h; substrate to water ratio=1.5. The minimum content of trypsin inhibitors was 6.4 mg g^-1 dry matter. The optimal conditions derived from RSM for A. oryzae fermentation were： substrate to water ratio= 0.8 1; inoculum size=4%; duration=120 h. The minimum content of trypsin inhibitors was 1.6 mg g^-1 dry matter. Both L. brevis and A. oryzae decreased trypsin inhibitors dramatically （57.1 and 89.2% respectively）. L. brevis fermentation did not affect phytic acid （0.4%） and crude fat （5.2%） considerably, whereas A. oryzae fermentation degraded phytic acid （34.8%） and crude fat （22.0%） contents to a certain extent. Crude protein content was increased after both fermentation （6.4 and 12.9% for L. brevis and A. oryzae respectively）. Urease activity was reduced greatly （83.3 and 58.3% for L. brevis and A. oryzae respectively）. In conclusion, SSF with A. oryzae and L. brevis reduced trypsin inhibitor content and modified major macronutrients in soybean meal.
文摘BACKGROUND: Urinary trypsin inhibitor (UTI) inhibits the inflammatory response and protects against ischemia-reperfusion (I/R) injury. The inflammatory response is mediated by nuclear factor-kappa B (NF-kappa B) and its related target genes and products such as vascular endothelial cell adhesion molecule and CXC chemokines. We aimed to assess the roles of those mediators in a UTI-treated mouse model of hepatic I/R injury. METHODS: Treatment group 1 (UTI given 5 minutes prior to liver ischemia), treatment group 2 (UTI given 5 minutes after the anhepatic phase) and a control group were investigated. Blood and liver samples were obtained and compared at 1, 3, 6 and 24 hours after reperfusion. RESULTS: Attenuation of pathological hepatocellular damage was greater in the treatment groups than in the control group (P < 0.05). Compared with the control group, the UTI treatment groups showed significantly lower serum alanine aminotransferase and aspartate aminotransferase levels, decreased myeloperoxidase activity, and reduced NF-kappa B activation. Also downregulated was the expression of tumor necrosis factor-alpha, cytokine-induced neutrophil chemoattractant, and macrophage inflammatory protein-2 at the mRNA level. P-selectin protein and intercellular adhesion molecule-1 protein expression were also downregulated. In addition, the treatment group I showed a better protective effect against I/R injury than the treatment group 2. CONCLUSIONS: UTI reduces NF-kappa B activation and downregulates the expression of its related mediators, followed by the inhibition of neutrophil aggregation and infiltration in hepatic I/R injury. The protective role of UTI is more effective in prevention than in treatment.
