“Whoa! It's like Spotify but for academic articles.”

Instant Access to Thousands of Journals for just $40/month

Get 2 Weeks Free

Ligand migration in the truncated hemoglobin of Mycobacterium tuberculosis

The truncated hemoglobin of Mycobacterium tuberculosis (Mt‐trHbO) is a small heme protein belonging to the hemoglobin superfamily. Truncated hemoglobins (trHbs) are believed to have functional roles such as terminal oxidases and oxygen sensors involved in the response to oxidative and nitrosative stress, nitric oxide (NO) detoxification, O2/NO chemistry, O2 delivery under hypoxic conditions, and long‐term ligand storage. Based on sequence similarities, they are classified into three groups. Experimental studies revealed that all trHbs display a 2‐on‐2 α‐helical sandwich fold rather than the 3‐on‐3 α‐helical sandwich fold of the classical hemoglobin fold. Using locally enhanced sampling (LESMD) molecular dynamics, the ligand‐binding escape pathways from the distal heme binding cavity of Mt‐trHbO were determined to better understand how this protein functions. The importance of specific residues, such as the group II and III invariant W(G8) residue, can be seen in terms of ligand diffusion pathways and ligand dynamics. LESMD simulations show that the wild‐type Mt‐trHbO has three diffusion pathways while the W(G8)F Mt‐trHbO mutant has only two. The W(G8) residue plays a critical role in ligand binding and stabilization and helps regulate the rate of ligand escape from the distal heme pocket. Thus, this invariant residue is important in creating ligand diffusion pathways and possibly in the enzymatic functions of this protein. © 2011 IUBMB IUBMB Life, 63(3): 214–220, 2011 http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png IUBMB Life Wiley

Loading next page...

You're reading a free preview. Subscribe to read the entire article.

And millions more from thousands of peer-reviewed journals, for just $40/month

Get 2 Weeks Free

To be the best researcher, you need access to the best research

  • With DeepDyve, you can stop worrying about how much articles cost, or if it's too much hassle to order — it's all at your fingertips. Your research is important and deserves the top content.
  • Read from thousands of the leading scholarly journals from Springer, Elsevier, Nature, IEEE, Wiley-Blackwell and more.
  • All the latest content is available, no embargo periods.