13C Natural Abundance S3E and S3CT Experiments for Measurement ofJCoupling Constants between13Cαor1Hαand Other Protons in a Protein

✍ Scribed by Morten Dahl Sørensen; Axel Meissner; Ole Winneche Sørensen

• Book ID: 102597570
• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 136 KB
• Volume: 137
• Category: Article
• ISSN: 1090-7807
• DOI: 10.1006/jmre.1998.1635

✦ Synopsis

It is demonstrated that the spin-state-selective pulse sequence elements, S 3 E and S 3 CT, previously introduced for measurement of J coupling constants in 15 N-labeled proteins can be applied for work with peptides and proteins with 13 C at the natural abundance level. In addition, a method is described for suppression of crosstalk caused by passive spin flips and pulse imperfections, which otherwise results in systematically underestimated J coupling constants and thereby inaccurate structural constraints. This method is also applicable for crosstalk suppression in applications of S 3 E and S 3 CT to 13 C-or 15 N-labeled samples. Experimental confirmation is obtained using a 10 mM BPTI sample focusing on 13 C in the ␣ position. The measured J coupling constants include 3 J(H N -H ␣ ) and 3 J(H ␣ -H ␤ ) related to the and 1 angles, respectively.