Triplin: Functional Probing of Its Structure and the Dynamics of the Voltage-Gating Process

dc.contributor.authorColombini, Marco
dc.contributor.authorBarnes, Kevin
dc.contributor.authorChang, Kai-Ti
dc.contributor.authorYounis, Muhsin H.
dc.contributor.authorAguilella, Vicente M.
dc.date.accessioned2023-10-17T14:51:51Z
dc.date.available2023-10-17T14:51:51Z
dc.date.issued2022-11-09
dc.description.abstractGram-negative bacteria have a large variety of channel-forming proteins in their outer membrane, generally referred to as porins. Some display weak voltage dependence. A similar trimeric channel former, named Triplin, displays very steep voltage dependence, rivaling that responsible for the electrical excitability of mammals, and high inter-subunit cooperativity. We report detailed insights into the molecular basis for these very unusual properties explored at the single-molecule level. By using chemical modification to reduce the charge on the voltage sensors, they were shown to be positively charged structures. Trypsin cleavage of the sensor eliminates voltage gating by cleaving the sensor. From asymmetrical addition of these reagents, the positively charged voltage sensors translocate across the membrane and are, thus, responsible energetically for the steep voltage dependence. A mechanism underlying the cooperativity was also identified. Theoretical calculations indicate that the charge on the voltage sensor can explain the rectification of the current flowing through the open pores if it is located near the pore mouth in the open state. All results support the hypothesis that one of the three subunits is oriented in a direction opposite to that of the other two. These properties make Triplin perhaps the most complex pore-forming molecular machine described to date.
dc.description.urihttps://doi.org/10.3390/ijms232213765
dc.identifierhttps://doi.org/10.13016/dspace/lflk-ygix
dc.identifier.citationColombini, M.; Barnes, K.; Chang, K.-T.; Younis, M.H.; Aguilella, V.M. Triplin: Functional Probing of Its Structure and the Dynamics of the Voltage-Gating Process. Int. J. Mol. Sci. 2022, 23, 13765.
dc.identifier.urihttp://hdl.handle.net/1903/31043
dc.language.isoen_US
dc.publisherMDPI
dc.relation.isAvailableAtCollege of Computer, Mathematical & Physical Sciencesen_us
dc.relation.isAvailableAtDigital Repository at the University of Marylanden_us
dc.relation.isAvailableAtBiologyen_us
dc.relation.isAvailableAtUniversity of Maryland (College Park, MD)en_us
dc.subjectvoltage dependence
dc.subjectvoltage sensor
dc.subjectporin
dc.subjectprokaryote
dc.subjectrectification
dc.subjecttrypsin
dc.subjectsingle channel
dc.subjectcooperativity
dc.subjectpore
dc.titleTriplin: Functional Probing of Its Structure and the Dynamics of the Voltage-Gating Process
dc.typeArticle
local.equitableAccessSubmissionNo

Files

Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
ijms-23-13765.pdf
Size:
5.47 MB
Format:
Adobe Portable Document Format
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.55 KB
Format:
Item-specific license agreed upon to submission
Description: