J-Multiplied HSQC (MJ-HSQC): A New Method for Measuring3J(HNHα) Couplings in15N-labeled Proteins
✍ Scribed by Sami Heikkinen; Helena Aitio; Perttu Permi; Rutger Folmer; Kari Lappalainen; Ilkka Kilpeläinen
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 88 KB
- Volume
- 137
- Category
- Article
- ISSN
- 1090-7807
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✦ Synopsis
A new method for the measurement of homonuclear 3 J(H N H ␣ ) coupling constants in 15 N-labeled small proteins is described. The method is based on a modified sensitivity enhanced HSQC experiment, where the 3 J(H N H ␣ ) couplings are multiplied in the f 1dimension. The J-multiplication of homonuclear 3 J(H N H ␣ ) couplings is based on simultaneous incrementation of 15 N chemical shift and homonuclear coupling evolution periods. The time increment for the homonuclear coupling evolution period is chosen to be a suitable multiple (2N ؋ t 1 ) of the corresponding increment for 15 N-shift evolution. This results in the splitting of the HSQC correlation in the f 1 -dimension by 2N ؋ 3 J(H N H ␣ ). Because the pulse sequence has good sensitivity and water suppression properties, it is particularly useful for natural abundance samples.