A modified two-stage soft-docking procedure was developed for the theoretic researches on the recognition of protein-protein or protein-peptide complexes. Some systems have been used to test our program and the result...A modified two-stage soft-docking procedure was developed for the theoretic researches on the recognition of protein-protein or protein-peptide complexes. Some systems have been used to test our program and the results are encouraging.展开更多
Strategies for insect population control are currently targeting chemical communication at the molecular level. The diamondback moth Plutella xylostella represents one of the most serious pests in agriculture, however...Strategies for insect population control are currently targeting chemical communication at the molecular level. The diamondback moth Plutella xylostella represents one of the most serious pests in agriculture, however detailed information on the proteins mediating olfaction in this species is still poor. This species is endowed with a repertoire of a large number of olfactory receptors and odorant binding proteins（OBPs）. As a contribution to map the specificities of these chemical sensors in the moth and eventually unrave l the complexity of chemodetection, we have measured the affinities of three selected OBPs to a series of potential odorants. Three proteins are highly divergent in their amino acid sequences and show markedly different expression profiles. In fact, PxylOBP3 is exclusively expressed in the antennae of both sexes, PxylOBP9 is male specific and present only in antennae and reproductive organs, while PxylOBP19, an unusual OBP with nine cysteines, is ubiquitously present in all the organs examined. Such expression pattern suggests that the last two proteins may be involved in non-chemosensory functions. Despite such differences, the three OBPs exhibit similar binding spectra, together with high selectivity. Among the 26 natural compounds tested, only two proved to be good ligands, retinol and coniferyl aldehyde. This second compound is particularly interesting being part of the chemical pathway leading to regeneration of lignin, one of the defense strategies of the plant against insect attack, and might find applications as a repellent for P. xylostella and other pests.展开更多
OBJECTIVE Palythoa caribaeorum(class Anthozoa) is a zoanthid that together jellyfishes,hydra,and sea anemones,which are venomous and predatory,belongs to the Phyllum Cnidaria.The distinguished feature in these marine ...OBJECTIVE Palythoa caribaeorum(class Anthozoa) is a zoanthid that together jellyfishes,hydra,and sea anemones,which are venomous and predatory,belongs to the Phyllum Cnidaria.The distinguished feature in these marine animals is the cnidocytes in the body tissues,responsible for toxin production and injection that are used majorly for prey capture and defense.With exception for other anthozoans,the toxin cocktails of zoanthids have been scarcely studied and are poorly known.METHODS Based on the analysis of P.caribaeorum transcriptome,numerous predicted venom-featured polypeptides were identified,including allergens,neuro-toxins,membrane-active and Kunitz-like peptides(PcKuz).The three predicted PcKuz isotoxins(1 to 3) were selected for functional studies.Through computational processing comprising structural phylogenetic analysis,molecular docking,and dynamics simulation,PcKuz3 was shown to be a potential voltage gated potassium-channel inhibitor.RESULTS PcKuz3 fitted well as new functional Kunitz-type toxins with strong anti-locomotor activity as in vivo assessed in zebrafish larvae,with weak inhibitory effect toward proteases,as evaluated in vitro.Notably,PcKuz3 can suppress,at low concentration,the 6-OHDA-induced neurotoxicity on the locomotive behavior of zebrafish,which indicated PcKuz3 may have a neuroprotective effect.CONCLUSION Taken together,PcK uz3 figures as a novel neurotoxin structure which differs from known homologous peptides expressed in sea anemone.Moreover,the novel PcKuz3 provides an insightful hint for bio-drug development for prospective neurodegenerative disease treatment.展开更多
Numerous transmethylation reactions are required for normal plant growth and development. S-adenosylhomocysteine hydrolase （SAHH） and adenosine kinase （ADK） act coordinately to recycle the by-product of these reac...Numerous transmethylation reactions are required for normal plant growth and development. S-adenosylhomocysteine hydrolase （SAHH） and adenosine kinase （ADK） act coordinately to recycle the by-product of these reactions, S-adenosylhomocysteine （SAH） that would otherwise competitively inhibit methyltransferase （MT） activities. Here, we report on investigations to understand how the SAH produced in the nucleus is metabolized by SAHH and ADK. Localization analyses using green fluorescent fusion proteins demonstrated that both enzymes are capable of localizing to the cytoplasm and the nucleus, although no obvious nuclear localization signal was found in their sequences. Deletion analysis revealed that a 41-amino-acid segment of SAHH （GlylS^-Lys19~） is required for nuclear targeting of this enzyme. This segment is surface exposed, shows unique sequence conservation patterns in plant SAHHs, and possesses additional features of protein-protein interaction motifs. ADK and SAHH interact in Arabidopsb via this segment and also interact with an mRNA cap MT. We propose that the targeting of this complex is directed by the nuclear localization signal of the MT; other MTs may similarly target SAHH/ADK to other subcellular compartments to ensure uninterrupted transmethylation.展开更多
文摘A modified two-stage soft-docking procedure was developed for the theoretic researches on the recognition of protein-protein or protein-peptide complexes. Some systems have been used to test our program and the results are encouraging.
基金supported by the National Natural Science Foundation of China (31230062 and 31321004)the Beijing Natural Science Foundation of China (6132028)the State Key Laboratory for Biology of Plant Diseases and Insect Pests, Chinese Academy of Agricultural Sciences (SKLOF201502)
文摘Strategies for insect population control are currently targeting chemical communication at the molecular level. The diamondback moth Plutella xylostella represents one of the most serious pests in agriculture, however detailed information on the proteins mediating olfaction in this species is still poor. This species is endowed with a repertoire of a large number of olfactory receptors and odorant binding proteins（OBPs）. As a contribution to map the specificities of these chemical sensors in the moth and eventually unrave l the complexity of chemodetection, we have measured the affinities of three selected OBPs to a series of potential odorants. Three proteins are highly divergent in their amino acid sequences and show markedly different expression profiles. In fact, PxylOBP3 is exclusively expressed in the antennae of both sexes, PxylOBP9 is male specific and present only in antennae and reproductive organs, while PxylOBP19, an unusual OBP with nine cysteines, is ubiquitously present in all the organs examined. Such expression pattern suggests that the last two proteins may be involved in non-chemosensory functions. Despite such differences, the three OBPs exhibit similar binding spectra, together with high selectivity. Among the 26 natural compounds tested, only two proved to be good ligands, retinol and coniferyl aldehyde. This second compound is particularly interesting being part of the chemical pathway leading to regeneration of lignin, one of the defense strategies of the plant against insect attack, and might find applications as a repellent for P. xylostella and other pests.
基金Macao Science and Technology Development Fund(017/2015/AMJ134/2014/A3).
文摘OBJECTIVE Palythoa caribaeorum(class Anthozoa) is a zoanthid that together jellyfishes,hydra,and sea anemones,which are venomous and predatory,belongs to the Phyllum Cnidaria.The distinguished feature in these marine animals is the cnidocytes in the body tissues,responsible for toxin production and injection that are used majorly for prey capture and defense.With exception for other anthozoans,the toxin cocktails of zoanthids have been scarcely studied and are poorly known.METHODS Based on the analysis of P.caribaeorum transcriptome,numerous predicted venom-featured polypeptides were identified,including allergens,neuro-toxins,membrane-active and Kunitz-like peptides(PcKuz).The three predicted PcKuz isotoxins(1 to 3) were selected for functional studies.Through computational processing comprising structural phylogenetic analysis,molecular docking,and dynamics simulation,PcKuz3 was shown to be a potential voltage gated potassium-channel inhibitor.RESULTS PcKuz3 fitted well as new functional Kunitz-type toxins with strong anti-locomotor activity as in vivo assessed in zebrafish larvae,with weak inhibitory effect toward proteases,as evaluated in vitro.Notably,PcKuz3 can suppress,at low concentration,the 6-OHDA-induced neurotoxicity on the locomotive behavior of zebrafish,which indicated PcKuz3 may have a neuroprotective effect.CONCLUSION Taken together,PcK uz3 figures as a novel neurotoxin structure which differs from known homologous peptides expressed in sea anemone.Moreover,the novel PcKuz3 provides an insightful hint for bio-drug development for prospective neurodegenerative disease treatment.
文摘Numerous transmethylation reactions are required for normal plant growth and development. S-adenosylhomocysteine hydrolase （SAHH） and adenosine kinase （ADK） act coordinately to recycle the by-product of these reactions, S-adenosylhomocysteine （SAH） that would otherwise competitively inhibit methyltransferase （MT） activities. Here, we report on investigations to understand how the SAH produced in the nucleus is metabolized by SAHH and ADK. Localization analyses using green fluorescent fusion proteins demonstrated that both enzymes are capable of localizing to the cytoplasm and the nucleus, although no obvious nuclear localization signal was found in their sequences. Deletion analysis revealed that a 41-amino-acid segment of SAHH （GlylS^-Lys19~） is required for nuclear targeting of this enzyme. This segment is surface exposed, shows unique sequence conservation patterns in plant SAHHs, and possesses additional features of protein-protein interaction motifs. ADK and SAHH interact in Arabidopsb via this segment and also interact with an mRNA cap MT. We propose that the targeting of this complex is directed by the nuclear localization signal of the MT; other MTs may similarly target SAHH/ADK to other subcellular compartments to ensure uninterrupted transmethylation.
