2014 Dale Webster Lecturer Announced
Description
A fellow of the National Academy of Sciences, India, will deliver the 2014 Dale Webster Lecture. Kanak L. Dikshit, a scientist with the CSIR (Council of Scientific & Industrial Research)-Institute of Microbial Technology will speak on “Truncated Hemoglobins: A New Group Within the Globin Family with Novel Structure and Function” on April 23 at 4 p.m. in the MTCC Auditorium. All are welcome. A reception will follow in the Pritzker Club. Please RSVP to Lauren Shelby at 312-567-5030 or rsvpevents@iit.edu.
Webster is an IIT biology professor emeritus who founded the field of bacterial hemoglobins in 1986. Since then, it has become a widely studied area—both in basic knowledge of hemoglobin structure, function, and evolution, and in the use of bacterial hemoglobins in many important practical applications, including the production of antibiotics and petrochemical replacements.
The IIT College of Science and the biology division established the lecture last year to honor Webster’s scholarship and many years of service to IIT.
Dikshit is a longtime collaborator of Webster’s. In a talk that will be of particular interest to biochemists, microbiologists, industrial biochemists and microbiologists, and medical and public health professionals, she will present novel aspects of the structure and biological function of some truncated hemoglobins.
Abstract
In the past 20 years, after the discovery of first hemoglobin in a bacterium, Vitreoscilla, the hemoglobin superfamily has been enriched by the discovery of new forms of globins that have provided novel insights into their structure and biological functions. Truncated hemoglobins (also known as 2/2 Hbs or trHbs) are a recent addition to the cluster of Hbs; they are 20-40 residues shorter than classical hemoglobins.
Their tertiary structure stems from extensive and complex modifications of the conventional globin fold, displaying four main helices that are interlinked with extended polypeptide loops and a protein matrix tunnel that facilitates diffusion of functional ligands to/from the heme active site. Three distinct phylogenetic groups of truncated Hbs have been identified based on their sequences and structural organization. Different classes of trHbs usually co-exist in one organism and perform distinct cellular function(s).
Some of the organisms hosting truncated Hbs are aggressive pathogenic bacteria, including the human pathogen Mycobacterium tuberculosis, which carries two truncated Hbs, HbN and HbO. These hemoglobins help the pathogen in evading host-defense mechanisms during intracellular infection by acting as efficient scavengers of toxic reactive oxygen/nitrogen species and supporting survival of their host under adverse environmental conditions. TrHbs may also be post-translationally modified in some cases and be involved in unconventional functions like signal-transduction, host-pathogen interactions, etc. Thus, the physiological functions of truncated hemoglobins may be various and quite diverse. Dikshit will describe the novel structure and biological functions of truncated hemoglobins as well as their applications.