biostudies-literature00640Idikuda VNIGMS NIH HHS1273-1286https://www.ebi.ac.uk/biostudies/studies/S-EPMC6122923biostudies-literatureUnknown150(9)Photochemically or metabolically generated singlet oxygen (¹O₂) reacts broadly with macromolecules in the cell. Because of its short lifetime and working distance, ¹O₂ holds potential as an effective and precise nanoscale tool for basic research and clinical practice. Here we investigate the modification of the spHCN channel that results from photochemically and chemically generated ¹O₂ The spHCN channel shows strong voltage-dependent inactivation in the absence of cAMP. In the presence of photosensitizers, short laser pulses transform the gating properties of spHCN by abolishing inactivation and increasing the macroscopic current amplitude. Alanine replacement of a histidine residue near the activation gate within the channel's pore abolishes key modification effects. Application of a variety of chemicals including ¹O₂ scavengers and ¹O₂ generators supports the involvement of ¹O₂ and excludes other reactive oxygen species. This study provides new understanding about the photodynamic modification of ion channels by ¹O₂ at the molecular level.The Journal of general physiologySinglet oxygen modification abolishes voltage-dependent inactivation of the sea urchin spHCN channel.PMC6122923R01 GM109193R01 GM098592Zhou LIdikuda VLiu QGao WGrant KSu Z64falseSinglet oxygen modification abolishes voltage-dependent inactivation of the sea urchin spHCN channel.Photochemically or metabolically generated singlet oxygen (¹O₂) reacts broadly with macromolecules in the cell. Because of its short lifetime and working distance, ¹O₂ holds potential as an effective and precise nanoscale tool for basic research and clinical practice. Here we investigate the modification of the spHCN channel that results from photochemically and chemically generated ¹O₂ The spHCN channel shows strong voltage-dependent inactivation in the absence of cAMP. In the presence of photosensitizers, short laser pulses transform the gating properties of spHCN by abolishing inactivation and increasing the macroscopic current amplitude. Alanine replacement of a histidine residue near the activation gate within the channel's pore abolishes key modification effects. Application of a variety of chemicals including ¹O₂ scavengers and ¹O₂ generators supports the involvement of ¹O₂ and excludes other reactive oxygen species. This study provides new understanding about the photodynamic modification of ion channels by ¹O₂ at the molecular level.2018-01-01T00:00:00Z2018 Sep2022-02-09T08:35:49.493Z2019-10-11T07:15:52ZS-EPMC61229233004214110.1085/jgp.201711961