Our Science – Wlodawer Website
Alexander Wlodawer, Ph.D.
Our Section investigates the relationship between protein structure and function, mainly by the technique of high-resolution X-ray diffraction. Some of the areas of interest are directly involved in elucidating structural features of the molecules that could explain their importance to understanding cancer and AIDS, but we are also active in the development of methods for protein crystallography.
Crystallographic studies of proteases
Crystallographic studies of proteases have been an important area of research of this Section since its establishment. We have been particularly active in the investigation of structure-function relationship in aspartic proteases, including clinically important retroviral enzymes. Our studies of HIV-1 protease, although no longer a major target of active research, are still ongoing and concentrate on the investigation of drug-resistant variants and their complexes with inhibitors. We have investigated structure-function relationship in retroviral proteases from several other sources such as FIV, RSV, EIAV, HTLV-1, and XMRV. Cockroach allergen Bla g 2 was shown to be an inactive aspartic protease and we solved its structure by itself, and in a complex with several specific antibodies. We have determined the structure of a unique histoaspartic protease, an enzyme with the pepsin fold, but a vastly different mechanism. We found that Shigella virulence factor VirA is a putative protease with a novel fold, and we are examining its structural and enzymatic properties. We have established an extensive program of investigating serine-carboxyl peptidases (sedolisins), a family that was first characterized based on crystal structures solved in this laboratory and that is found in many different organisms. We are also investigating the bacterial ATP-dependent protease Lon, having found that its proteolytic domain has a unique fold and thus establishes a new family of proteases with a Ser-Lys catalytic dyad. We have solved the structures of the proteolytic domain of A and B type Lon proteases, encoded by E. coli and Archaeoglobus fulgidus, as well as the N-terminal and α domains of E. coli Lon.
Cytokines and cytokine receptors
Our Section has been investigating the crystal structures of several cytokines and their receptor complexes. We are focused on the cytokines that belong to the IL-10 family such as IL-19, IL-20, IL-22, IFN-λ1 and IFN-λ2, and on the receptors that are shared by the family members. We already solved crystal structures of IL-10 and IL-19, and of a complex of IFN-λ1 with IFN-λR1, whereas studies on other complexes are ongoing. We are also investigating the intracellular domains of the receptors complexed with JAK kinases.
Lectins with Antiviral Activity
We have been involved in studies of several lectins with antiviral activities, some of them used in pre-clinical trials as potential drugs preventing HIV infection. We have solved the structure of griffithsin, as free protein and complexed with a number of mono- and disaccharides, explaining the structural basis for its tight binding to branched mannose-rich carbohydrates. We have reengineered griffithsin into a monomeric form and determined its structure in complex with branched carbohydrates. We have also solved the structure of another lectin, scytovirin, and are investigating its mode of carbohydrate binding.
Our extramural collaborators include Anna Marie Skalka, Ph.D., Fox Chase Cancer Center; Ben Dunn, Ph.D., University of Florida; John Elder, Ph.D., The Scripps Research Institute; Rickey Yada, Ph.D., University of Guelph, Guelph, Canada; Mariusz Jaskolski, D.Sc., Adam Mickiewicz University, Poznan, Poland; and Tatyana Rotanova, D.Sc., Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Moscow, Russia.
This page was last updated on 4/12/2013.