Cellulose binding domains (CBDs) are present in the majority of fungal cellulases and hemicellulases. Based on the conserved region of CBDs, degenerate primers were designed and used to amplify the 5′ end cDNA fragme...Cellulose binding domains (CBDs) are present in the majority of fungal cellulases and hemicellulases. Based on the conserved region of CBDs, degenerate primers were designed and used to amplify the 5′ end cDNA fragment of xylanase from Volvariella volvacea by 5′ RACE. Gene specific primer was then designed based on extreme region of 5′ end cDNA fragment and used to amplify the full length cDNA of xylanase. The cDNA of xyn 1 was 1 287 bp in length, including 3′ and 5′ non coding region. The xyn 1 cDNA contained an ORF of 1101 bp encoding 367 amino acids, in which there was a putative signal peptide with 19 amino acids. Alignment of the deduced amino acid sequence of xyn 1 with other xylanases showed that the homology with family 10 xylanases from Agaricus bisporus xyl1,Aspergillus sojae xyn1, Aspergillus kawachii xynA, Fusarium oxysporum f.sp xyl3 was 64%,55%,52%,55%, respectively.展开更多
Current fire retardants are known to be toxic to humans and our environment.As environmental-friendly flame retardants(FRs),protein-based flame retardants have been studied extensively recently,even though they are no...Current fire retardants are known to be toxic to humans and our environment.As environmental-friendly flame retardants(FRs),protein-based flame retardants have been studied extensively recently,even though they are not durable.In this study,we designed,synthesized and tested a durable protein-based FR through the fusion of the adhesion domain from either mussel foot protein-5(mfp-5)or cellulose-binding domain(CBD)with flame retardant protein(SR protein and alpha casein).We first verified the expression of the recombinant proteins in Escherichia coli using Western blot.Then,we coated the fusion protein(carrying cell lysates)to cotton fabrics and wood and verified with Infrared(IR)spectroscopy.Using a vertical burning test and wood flammability test,we confirmed the flame retardancy of the materials after the protein coating.In the vertical burning test,the SR protein and alpha casein flame retardant proteins with the CBD adhesion domain showed a 50.0%and 43.3%increase in flame retardancy.The data is also consistent in the wood flame retardancy test.Confocal imaging experiments also suggested these new fire retardants can be preserved on the materials well even after washing.Overall,our results showed that flame-retardant proteins with adhesion domains are high potential candidates of green alternative flame retardants.展开更多
文摘Cellulose binding domains (CBDs) are present in the majority of fungal cellulases and hemicellulases. Based on the conserved region of CBDs, degenerate primers were designed and used to amplify the 5′ end cDNA fragment of xylanase from Volvariella volvacea by 5′ RACE. Gene specific primer was then designed based on extreme region of 5′ end cDNA fragment and used to amplify the full length cDNA of xylanase. The cDNA of xyn 1 was 1 287 bp in length, including 3′ and 5′ non coding region. The xyn 1 cDNA contained an ORF of 1101 bp encoding 367 amino acids, in which there was a putative signal peptide with 19 amino acids. Alignment of the deduced amino acid sequence of xyn 1 with other xylanases showed that the homology with family 10 xylanases from Agaricus bisporus xyl1,Aspergillus sojae xyn1, Aspergillus kawachii xynA, Fusarium oxysporum f.sp xyl3 was 64%,55%,52%,55%, respectively.
基金We thank Prof.Leo Tsz On LEE Prof.Ruiyu XIE and Prof.Tzu-Ming LIU for discussions and conceptual support,Stephanie Pei Wen NG and Weng I LEI for technical support,and all other members/contributors in the PuiChing 2020 team(Ieng Chon LI,Yi Fan XIANG,Sin Mei CHEONG,Cho Cheng SHE,Weng Seong LEI,Pak Chong CHEONG,Chan In NG,Nga Chi LEONG,Teng Wai HOI,Weng Si CHIO,Lok Hang CHIU,Hou IONG,Weng In LAI,Jeremy HU,Franklin YEUNG,Hao Nian MIN,Hau Yin LEUNG and Yating MO)for helping this project.We also thank the Wynn Care,Science and Technology Development Fund(FDCT)(Grand code:0016/2020/PS),Institute for the Development and Quality(IDQ)and Faculty of Health Sciences,University of Macao for supporting this work.
文摘Current fire retardants are known to be toxic to humans and our environment.As environmental-friendly flame retardants(FRs),protein-based flame retardants have been studied extensively recently,even though they are not durable.In this study,we designed,synthesized and tested a durable protein-based FR through the fusion of the adhesion domain from either mussel foot protein-5(mfp-5)or cellulose-binding domain(CBD)with flame retardant protein(SR protein and alpha casein).We first verified the expression of the recombinant proteins in Escherichia coli using Western blot.Then,we coated the fusion protein(carrying cell lysates)to cotton fabrics and wood and verified with Infrared(IR)spectroscopy.Using a vertical burning test and wood flammability test,we confirmed the flame retardancy of the materials after the protein coating.In the vertical burning test,the SR protein and alpha casein flame retardant proteins with the CBD adhesion domain showed a 50.0%and 43.3%increase in flame retardancy.The data is also consistent in the wood flame retardancy test.Confocal imaging experiments also suggested these new fire retardants can be preserved on the materials well even after washing.Overall,our results showed that flame-retardant proteins with adhesion domains are high potential candidates of green alternative flame retardants.
