pH-dependent conformational changes of KcsA tetramer and monomer probed by raman spectroscopy.
    
    
        
    
    
        
        Int. J. Mol. Sci. 20:2736 (2019)
    
    
    
      
      
	
	    KcsA is a tetrameric potassium channel formed out of four identical monomeric subunits used as a standard model for selective potassium transport and pH-dependent gating. Large conformational changes are reported for tetramer and monomer upon gating, and the response of the monomer being controversial with the two major studies partially contradicting each other. KcsA was analyzed as functional tetramers embedded in liposomes and as monomer subunits with confocal Raman microscopy under physiological conditions for the active and the closed channel state, using 532 nm excitation to avoid introducing conformational changes during the measurement. Channel function was confirmed using liposome flux assay. While the classic fingerprint region below 1800 rel. cm(-1) in the Raman spectrum of the tetramer was unaffected, the CH-stretching region between 2800 and 3200 rel. cm(-1) was found to be strongly affected by the conformation. No pH-dependency was observed in the Raman spectra of the monomer subunits, which closely resembled the Raman spectrum of the tetramer in its active conformation, indicating that the open conformation of the monomer and not the closed conformation as postulated may equal the relaxed state of the molecule.
	
	
	    
	
       
      
	
	    
		Impact Factor
		Scopus SNIP
		Web of Science
Times Cited
		Scopus
Cited By
		Altmetric
		
	     
	    
	 
       
      
     
    
        Publication type
        Article: Journal article
    
 
    
        Document type
        Scientific Article
    
 
    
        Thesis type
        
    
 
    
        Editors
        
    
    
        Keywords
        532 Nm ; Kcsa ; Raman Spectroscopy ; Liposome Flux Assay ; Monomer ; Ph-dependent Gating ; Tetramer; Potassium Channels; Cytoplasmic Domain; Molecular-basis; Ion-channel; Selectivity; Conduction; Lipids
    
 
    
        Keywords plus
        
    
 
    
    
        Language
        english
    
 
    
        Publication Year
        2019
    
 
    
        Prepublished in Year
        
    
 
    
        HGF-reported in Year
        2019
    
 
    
    
        ISSN (print) / ISBN
        1661-6596
    
 
    
        e-ISSN
        1422-0067
    
 
    
        ISBN
        
    
    
        Book Volume Title
        
    
 
    
        Conference Title
        
    
 
	
        Conference Date
        
    
     
	
        Conference Location
        
    
 
	
        Proceedings Title
        
    
 
     
	
    
        Quellenangaben
        
	    Volume: 20,  
	    Issue: 11,  
	    Pages: ,  
	    Article Number: 2736 
	    Supplement: ,  
	
    
 
    
        
            Series
            
        
 
        
            Publisher
            MDPI
        
 
        
            Publishing Place
            Basel
        
 
	
        
            Day of Oral Examination
            0000-00-00
        
 
        
            Advisor
            
        
 
        
            Referee
            
        
 
        
            Examiner
            
        
 
        
            Topic
            
        
 
	
        
            University
            
        
 
        
            University place
            
        
 
        
            Faculty
            
        
 
    
        
            Publication date
            0000-00-00
        
 
         
        
            Application date
            0000-00-00
        
 
        
            Patent owner
            
        
 
        
            Further owners
            
        
 
        
            Application country
            
        
 
        
            Patent priority
            
        
 
    
        Reviewing status
        Peer reviewed
    
 
    
        Institute(s)
        Institute of Medicinal Chemistry (IMC)
    
 
    
        POF-Topic(s)
        30203 - Molecular Targets and Therapies
    
 
    
        Research field(s)
        Enabling and Novel Technologies
    
 
    
        PSP Element(s)
        G-506300-001
    
 
    
        Grants
        
    
 
    
        Copyright
        
    
 	
    
    
    
    
    
        Erfassungsdatum
        2019-06-13