View Single Post
  #1  
Unread 08-21-2010, 11:12 PM
nmrlearner's Avatar
nmrlearner nmrlearner is offline
Senior Member
 
Join Date: Jan 2005
Posts: 23,135
Points: 193,617, Level: 100
Points: 193,617, Level: 100 Points: 193,617, Level: 100 Points: 193,617, Level: 100
Level up: 0%, 0 Points needed
Level up: 0% Level up: 0% Level up: 0%
Activity: 50.7%
Activity: 50.7% Activity: 50.7% Activity: 50.7%
Last Achievements
Award-Showcase
NMR Credits: 0
NMR Points: 0
Downloads: 0
Uploads: 0
Default Conformational studies on a peptide fragment representing the RNA-binding N-terminus

Conformational studies on a peptide fragment representing the RNA-binding N-terminus of a viral coat protein using circular dichroism and NMR spectroscopy.

Related Articles Conformational studies on a peptide fragment representing the RNA-binding N-terminus of a viral coat protein using circular dichroism and NMR spectroscopy.

Eur J Biochem. 1991 Oct 15;201(2):489-94

Authors: van der Graaf M, Hemminga MA

Conformational studies were performed on a synthetic pentacosapeptide representing the RNA-binding N-terminal region of the coat protein of cowpea chlorotic mottle virus. The effects of ionic strength, addition of (oligo)phosphates and temperature on the conformation of this highly positively charged peptide containing six arginines and three lysines were studied. CD experiments show that the peptide has 15-18% alpha-helical conformation and about 80% random-coil conformation in the absence of inorganic salt at 25 degrees C, and 20-21% alpha-helical conformation under the same conditions at 10 degrees C. Addition of inorganic salts results in an increase of alpha-helix content, up to 42% in the presence of oligophosphate with an average chain length of 18 phosphates, which was used as an RNA analog. NMR experiments show that the alpha-helix formation starts in the region between Thr9 and Gln12, and is extended in the direction of the C terminus. Relaxation measurements show that binding to oligophosphates of increasing length results in reduced internal mobilities of the positively charged side chains of the arginyl and lysyl residues and of the side chain of Thr9 in the alpha-helical region. The alpha-helix formation in the N-terminal part of this viral coat protein upon binding of phosphate groups to the positively charged side chains is suggested to play an essential role in RNA binding.

PMID: 1935944 [PubMed - indexed for MEDLINE]



Source: PubMed
Reply With Quote


Did you find this post helpful? Yes | No