Aim: To produce biologically active recombinant human (rh) ZP proteins in a human cell for use in sperm function tests. Methods: The human embryonic kidney cell line 293T was employed to produce rhZP1, rhZP2 and rhZP3...Aim: To produce biologically active recombinant human (rh) ZP proteins in a human cell for use in sperm function tests. Methods: The human embryonic kidney cell line 293T was employed to produce rhZP1, rhZP2 and rhZP3 proteins individually and together by co-expression. Presence of these proteins in the culture medium and cell lysate was assessed by Western blotting analysis. The effect of the recombinant proteins on the human AR was assessed. Results: RhZP2 and rhZP3 were secreted into the culture medium, whereas rhZPl was found only in the cell lysate. Interestingly, when all zona pellucida proteins were co-expressed in the same cells, rhZPl was also secreted into the culture medium. However, despite the presence of all three ZP proteins in sufficient concentration and evidence of heavy glycosylation on gel electrophoresis, biological activity to induce the AR was not observed. Conclusion: RhZP1, rhZP2 and rhZP3 were successfully expressed in the human embryonic kidney cell line 293T. It appears that an interaction amongst these proteins may be required for release of rhZPl from the cell. Although this approach is not satisfactory for producing active human ZP proteins, it makes a significant contribution to the understanding of the structural and functional characteristics of the ZP proteins.展开更多
Bone collagen hydrolysates(peptides)derived from byproduct of animal product processing have been used to produce commercially valuable products due to their potential antioxidant activity.Maillard glycosylated reacti...Bone collagen hydrolysates(peptides)derived from byproduct of animal product processing have been used to produce commercially valuable products due to their potential antioxidant activity.Maillard glycosylated reaction is considered as a promising method to enhance the antioxidant activity of peptides.Hence,this research aims at investigating the Maillard glycosylation activity and antioxidant activity of bone collagen hydrolysates from different sources.In this study,3 glycosylated bone collagen hydrolysates were prepared and characterized,and cytotoxicity and antioxidant activity were analyzed and evaluated.The free amino groups loss,browning intensity,and fluorescence intensity of G-Cbcp(glycosylated chicken bone collagen hydrolysates(peptides))were the heaviest,followed by G-Pbcp(glycosylated porcine bone collagen hydrolysates(peptides))and G-Bbcp(glycosylated bovine bone collagen hydrolysates(peptides)).The results of amino acid analysis showed that amino acid composition of different bone collagen hydrolysates was significantly different and the amino acid decreased to different degrees after Maillard glycosylated reaction,which may lead to differences in Maillard glycosylated reaction activity.Furthermore,the 3 glycosylated hydrolysates showed no significant cytotoxicity.The results showed that glycosylation process significantly increased the antioxidant activity of bone collagen hydrolysates,and G-Cbcp showed the strongest antioxidant activity,followed by G-Pbcp and G-Bbcp.Therefore,compared with the bone collagen hydrolysates,3 glycosylated hydrolysates showed significant characteristic and structural changes,and higher antioxidant activity.展开更多
The discovery of Kahne glycosylation forwards a big step in the carbohydrate chemistry.Despite an extensive series of studies,the precise mechanism of this powerful glycosylation is still not fully understood.To addre...The discovery of Kahne glycosylation forwards a big step in the carbohydrate chemistry.Despite an extensive series of studies,the precise mechanism of this powerful glycosylation is still not fully understood.To address these 30-year puzzles,the far side of Kahne glycosylation is explored in this study.After a series of control and tracking experiments,a number of important intermediates including glycosyl oxo-sulfonium ion and sulfenic anhydride(Crich's intermediate)are suggested to be responsible for the complex reaction pathway.It also reveals that in addition to the conventional ionic glycosylation pathway,a novel free radical pathway is very likely to contribute to the various side-and co-products.This study provides further understanding of Kahne glycosylation,and it also sheds light on how to improve the efficiency of sulfoxide-based glycosylation reactions.展开更多
文摘Aim: To produce biologically active recombinant human (rh) ZP proteins in a human cell for use in sperm function tests. Methods: The human embryonic kidney cell line 293T was employed to produce rhZP1, rhZP2 and rhZP3 proteins individually and together by co-expression. Presence of these proteins in the culture medium and cell lysate was assessed by Western blotting analysis. The effect of the recombinant proteins on the human AR was assessed. Results: RhZP2 and rhZP3 were secreted into the culture medium, whereas rhZPl was found only in the cell lysate. Interestingly, when all zona pellucida proteins were co-expressed in the same cells, rhZPl was also secreted into the culture medium. However, despite the presence of all three ZP proteins in sufficient concentration and evidence of heavy glycosylation on gel electrophoresis, biological activity to induce the AR was not observed. Conclusion: RhZP1, rhZP2 and rhZP3 were successfully expressed in the human embryonic kidney cell line 293T. It appears that an interaction amongst these proteins may be required for release of rhZPl from the cell. Although this approach is not satisfactory for producing active human ZP proteins, it makes a significant contribution to the understanding of the structural and functional characteristics of the ZP proteins.
基金supported by the National Natural Science Foundation of China(32101883)Fellowship China Postdoctoral Science Foundation(2021M693902)National Agricultural Science and Technology Innovation Project(CAAS-ASTIP-2022)。
文摘Bone collagen hydrolysates(peptides)derived from byproduct of animal product processing have been used to produce commercially valuable products due to their potential antioxidant activity.Maillard glycosylated reaction is considered as a promising method to enhance the antioxidant activity of peptides.Hence,this research aims at investigating the Maillard glycosylation activity and antioxidant activity of bone collagen hydrolysates from different sources.In this study,3 glycosylated bone collagen hydrolysates were prepared and characterized,and cytotoxicity and antioxidant activity were analyzed and evaluated.The free amino groups loss,browning intensity,and fluorescence intensity of G-Cbcp(glycosylated chicken bone collagen hydrolysates(peptides))were the heaviest,followed by G-Pbcp(glycosylated porcine bone collagen hydrolysates(peptides))and G-Bbcp(glycosylated bovine bone collagen hydrolysates(peptides)).The results of amino acid analysis showed that amino acid composition of different bone collagen hydrolysates was significantly different and the amino acid decreased to different degrees after Maillard glycosylated reaction,which may lead to differences in Maillard glycosylated reaction activity.Furthermore,the 3 glycosylated hydrolysates showed no significant cytotoxicity.The results showed that glycosylation process significantly increased the antioxidant activity of bone collagen hydrolysates,and G-Cbcp showed the strongest antioxidant activity,followed by G-Pbcp and G-Bbcp.Therefore,compared with the bone collagen hydrolysates,3 glycosylated hydrolysates showed significant characteristic and structural changes,and higher antioxidant activity.
基金The National Natural Science Foundation of China(22025102,22077039,21877043)the Open Projects Fund of Shandong Key Laboratory of Carbohydrate Chemistry and Glycobiology,Shandong University(2021CCG02)the Fundamental Research Funds fortheCentralUniversities,HUST(2019kfyXKJC080,2019JYCXJJ046,2019kfyRCPY034)were appreciated.
文摘The discovery of Kahne glycosylation forwards a big step in the carbohydrate chemistry.Despite an extensive series of studies,the precise mechanism of this powerful glycosylation is still not fully understood.To address these 30-year puzzles,the far side of Kahne glycosylation is explored in this study.After a series of control and tracking experiments,a number of important intermediates including glycosyl oxo-sulfonium ion and sulfenic anhydride(Crich's intermediate)are suggested to be responsible for the complex reaction pathway.It also reveals that in addition to the conventional ionic glycosylation pathway,a novel free radical pathway is very likely to contribute to the various side-and co-products.This study provides further understanding of Kahne glycosylation,and it also sheds light on how to improve the efficiency of sulfoxide-based glycosylation reactions.
