Fagopyrum esculentum(buckwheat,Polygonaceae)is a multi-food-use pseudocereal with healing benefits and is growing on arid areas.(1)Based on homology and RACE method,aRD21 orthologous gene from buckwheat was isolated a...Fagopyrum esculentum(buckwheat,Polygonaceae)is a multi-food-use pseudocereal with healing benefits and is growing on arid areas.(1)Based on homology and RACE method,aRD21 orthologous gene from buckwheat was isolated and identified.The RD21 homologous gene fromF.esculentumtranscript was1750 bp and contained a 1407 bp ORF(Open Reading Frame,ORF)encoding 468 amino acids.(2)Protein sequence alignment and phylogenetic analyses grouped FeRD21 into PLCPs subfamily members which carry a C-terminal granulin domain.(3)The protease of FeRD21 was highly conserved and harbored the conservation sites of catalytic residues Cys168-His304-Asn324.(4)Expression analysis suggested that FeRD21 was up-regulated by salt,dehydration,ABA,and senescent treatments,which showed a different way in response to stresses with RD21 in Arabidopsis.Our results indicated that FeRD21 might be involved the stress-responsive pathways in F.esculentum.展开更多
Aim Head and neck cancers are the eighth most common cancer worldwide. Despite significant ad- vances in the delivery of treatment and surgical reconstruction, the mortality rates for this disease have not improved in...Aim Head and neck cancers are the eighth most common cancer worldwide. Despite significant ad- vances in the delivery of treatment and surgical reconstruction, the mortality rates for this disease have not improved in the past 4 decades. Our previous study has shown that HIV protease inhibitors （HIV PIs） induce cell apoptosis via activating endoplasmic reticulum （ER） stress. It also has been reported that a few HIV PIs are able to radio- sensitize tumor cells. However, the underlying cellular mechanisms remain to be identified. The aim of this study was to examine whether HIV PIs activate the ER stress response and sensitize human head and neck carcinoma cells to radiation. Methods Human SQ20B and Fadu cells and the most commonly used HIV PIs, lopinavir and ritona- vir, were used in this study. The mRNA and protein levels of ER stress-related genes （ CHOP, ATF4, XBP-1, and GRP78 ） were detected by real time RT-PCR and Western blot, respectively. Cell viability and apoptosis were ana- lyzed using Cellometer Vision CBA. After treatment with HIV PIs, cells were irradiated at a dose of 2G or 4G. Col- onies were stained and counted 10 days after irradiation. Results HIV PIs significantly induced activation of ER stress and apoptosis. Treatment of HIV PIs inhibited Akt phosphorylation, induced cell cycle arrest in G1 phase and increased tumor cell sensitivity to irradiation-induced cell death. Conclusion HIV PIs sensitize human head and neck carcinoma cells to radiation by activating ER stress.展开更多
Cod muscle protein was hydrolyzed by an alkaline protease in our study. The influences of hydrolysis temperature,fish protein concentration,and ratio of protease addition to protein amount on its degree of hy- drolysi...Cod muscle protein was hydrolyzed by an alkaline protease in our study. The influences of hydrolysis temperature,fish protein concentration,and ratio of protease addition to protein amount on its degree of hy- drolysis (DH) of protein were studied in details by applying dual quadratic rotary combinational design. The final results showed that more than 84% cod muscle protein could be hydrolyzed and recovered. Cod protein hydrolysate thus obtained had a balanced amino acid composition and mainly consisted of small peptides with molecule weight less than 6900 dalton.展开更多
The capacity of five enzymes (P1-P5) to inactivate the trypsin inhibitory activity (TIA) and lectin in raw soybean (RS) and low temperature-extruded soybean (LTES) was examined. P1 is an acid fungal protease with pH o...The capacity of five enzymes (P1-P5) to inactivate the trypsin inhibitory activity (TIA) and lectin in raw soybean (RS) and low temperature-extruded soybean (LTES) was examined. P1 is an acid fungal protease with pH optimum of 5 and P2, P3, P4 and P5 are bacterial proteases with pH optima of 7, 10, 8 and 8 respectively. The results indicated that all enzymes could reduce TIA to a varying degree at their optimum pH. The sequence of effectiveness was P3>P4>P5>P1>P2. The most effective enzyme, P3, reduced TIA to 38% and chymotrypsim inhibitory activity (CIA) to 9% of the original values. After six hours incubation at 50℃, the lectin concentration of LTES and RS was reduced by 50 and 17% respectively by P3, and by 42 and 29% by P4. In the second study, the best enzymes, P3 and P4, were incubated with RS or LTEs at different doses of 0, 0.10, 0.50% or 1.00% (w/w), for periods of 1, 2, 3, 6 or 12 hours. After one hour incubation with P3 at 1.00%, TIA of RS was reduced from 36.60 to 13.30 mg·g -1 . The corresponding values for LTES were 24.50 and 1.90 mg·g -1 . When the incubation was extended to 12 hours, the remaining TIA was 0.90 for LTES and 1.20 mg·g -1 for RS. P4 was not as effective as P3 up to six-hour incubation, but after twelve hours it achieved a similar reduction in activity to that of P3. A kinetic analysis of data showed that the inactivation process of purified soyabean trypsin inhibitors by P3 followed first-order chemical kinetics (Ct=90.90 -0.0408t , r=0.99). The rate of denaturation was -0.0408 per minute. It is concluded that the use of selected enzymes for anti-nutritive factors (ANFs) is an exciting possibility, but still requires further development.展开更多
文摘Fagopyrum esculentum(buckwheat,Polygonaceae)is a multi-food-use pseudocereal with healing benefits and is growing on arid areas.(1)Based on homology and RACE method,aRD21 orthologous gene from buckwheat was isolated and identified.The RD21 homologous gene fromF.esculentumtranscript was1750 bp and contained a 1407 bp ORF(Open Reading Frame,ORF)encoding 468 amino acids.(2)Protein sequence alignment and phylogenetic analyses grouped FeRD21 into PLCPs subfamily members which carry a C-terminal granulin domain.(3)The protease of FeRD21 was highly conserved and harbored the conservation sites of catalytic residues Cys168-His304-Asn324.(4)Expression analysis suggested that FeRD21 was up-regulated by salt,dehydration,ABA,and senescent treatments,which showed a different way in response to stresses with RD21 in Arabidopsis.Our results indicated that FeRD21 might be involved the stress-responsive pathways in F.esculentum.
文摘Aim Head and neck cancers are the eighth most common cancer worldwide. Despite significant ad- vances in the delivery of treatment and surgical reconstruction, the mortality rates for this disease have not improved in the past 4 decades. Our previous study has shown that HIV protease inhibitors （HIV PIs） induce cell apoptosis via activating endoplasmic reticulum （ER） stress. It also has been reported that a few HIV PIs are able to radio- sensitize tumor cells. However, the underlying cellular mechanisms remain to be identified. The aim of this study was to examine whether HIV PIs activate the ER stress response and sensitize human head and neck carcinoma cells to radiation. Methods Human SQ20B and Fadu cells and the most commonly used HIV PIs, lopinavir and ritona- vir, were used in this study. The mRNA and protein levels of ER stress-related genes （ CHOP, ATF4, XBP-1, and GRP78 ） were detected by real time RT-PCR and Western blot, respectively. Cell viability and apoptosis were ana- lyzed using Cellometer Vision CBA. After treatment with HIV PIs, cells were irradiated at a dose of 2G or 4G. Col- onies were stained and counted 10 days after irradiation. Results HIV PIs significantly induced activation of ER stress and apoptosis. Treatment of HIV PIs inhibited Akt phosphorylation, induced cell cycle arrest in G1 phase and increased tumor cell sensitivity to irradiation-induced cell death. Conclusion HIV PIs sensitize human head and neck carcinoma cells to radiation by activating ER stress.
文摘Cod muscle protein was hydrolyzed by an alkaline protease in our study. The influences of hydrolysis temperature,fish protein concentration,and ratio of protease addition to protein amount on its degree of hy- drolysis (DH) of protein were studied in details by applying dual quadratic rotary combinational design. The final results showed that more than 84% cod muscle protein could be hydrolyzed and recovered. Cod protein hydrolysate thus obtained had a balanced amino acid composition and mainly consisted of small peptides with molecule weight less than 6900 dalton.
文摘The capacity of five enzymes (P1-P5) to inactivate the trypsin inhibitory activity (TIA) and lectin in raw soybean (RS) and low temperature-extruded soybean (LTES) was examined. P1 is an acid fungal protease with pH optimum of 5 and P2, P3, P4 and P5 are bacterial proteases with pH optima of 7, 10, 8 and 8 respectively. The results indicated that all enzymes could reduce TIA to a varying degree at their optimum pH. The sequence of effectiveness was P3>P4>P5>P1>P2. The most effective enzyme, P3, reduced TIA to 38% and chymotrypsim inhibitory activity (CIA) to 9% of the original values. After six hours incubation at 50℃, the lectin concentration of LTES and RS was reduced by 50 and 17% respectively by P3, and by 42 and 29% by P4. In the second study, the best enzymes, P3 and P4, were incubated with RS or LTEs at different doses of 0, 0.10, 0.50% or 1.00% (w/w), for periods of 1, 2, 3, 6 or 12 hours. After one hour incubation with P3 at 1.00%, TIA of RS was reduced from 36.60 to 13.30 mg·g -1 . The corresponding values for LTES were 24.50 and 1.90 mg·g -1 . When the incubation was extended to 12 hours, the remaining TIA was 0.90 for LTES and 1.20 mg·g -1 for RS. P4 was not as effective as P3 up to six-hour incubation, but after twelve hours it achieved a similar reduction in activity to that of P3. A kinetic analysis of data showed that the inactivation process of purified soyabean trypsin inhibitors by P3 followed first-order chemical kinetics (Ct=90.90 -0.0408t , r=0.99). The rate of denaturation was -0.0408 per minute. It is concluded that the use of selected enzymes for anti-nutritive factors (ANFs) is an exciting possibility, but still requires further development.
