Брагин Павел Евгеньевич


Инженер (Лаборатория биомолекулярной ЯМР-спектроскопии)

Эл. почта: bragin@nmr.ru

Избранные публикации

  1. Bocharova O.V., Bragin P.E., Bocharov E.V., Mineev K.S., Goncharuk S.A., Arseniev A.S. (2016). Cell Free Expression and Purification of the Fragments of the Receptor Tyrosine Kynases of the EGFR Family, Containing the Transmembrane Domain with the Juxtamembrane Region, for Structural Studies. BIOLOGICHESKIE MEMBRANY 33 (2), 124–132 [+]

    The EGFR/HER receptor family of an epidermal growth factor represents an important class of the receptor tyrosine kinases playing the key role in the control of cell growth and differentiation in mammalian cells, as well as in the development of a number of pathological processes, including oncogenesis. Binding of a ligand to the extracellular domains initiates switching of the EGFR/HER receptor between the alternative dimeric states that causes the allosteric activation of kinase domains in cell cytoplasm. The transmembrane (TM) domain and adjacent flexible regions alternatively interacting with either membrane surface or kinase domains are directly involved in the complex conformational transition in EGFR/HERs. Here we report on a highly efficient system of the cell free production of the EGFR/HER TM domains with functionally important juxtamembrane (JM) regions for the investigation of the molecular basis of biochemical signal transduction across the cell membrane. To increase the efficiency of synthesis of the EGFR/HER TM-JM fragments of the receptors, we used two N-terminal expression tags, which significantly increased the protein yield. In the case of the TM-JM fragments of EGFR (residues 638–692) and HER2 (residues 644–700), the method allowed us to obtain milligram quantities of the 13C,15N-labeled protein for structural and biophysical investigations in the membrane-mimicking environments using high-resolution heteronuclear NMR spectroscopy.

    ID:1622
  2. Bragin P.E., Mineev K.S., Bocharova O.V., Volynsky P.E., Bocharov E.V., Arseniev A.S. (2016). HER2 Transmembrane Domain Dimerization Coupled with Self-Association of Membrane-Embedded Cytoplasmic Juxtamembrane Regions. J. Mol. Biol. 428 (1), 52–61 [+]

    Receptor tyrosine kinases of the human epidermal growth factor receptor (HER or ErbB) family transduce biochemical signals across plasma membrane, playing a significant role in vital cellular processes and in various cancers. Inactive HER/ErbB receptors exist in equilibrium between the monomeric and unspecified pre-dimerized states. After ligand binding, the receptors are involved in strong lateral dimerization with proper assembly of their extracellular ligand-binding, single-span transmembrane, and cytoplasmic kinase domains. The dimeric conformation of the HER2 transmembrane domain that is believed to support the cytoplasmic kinase domain configuration corresponding to the receptor active state was previously described in lipid bicelles. Here we used high-resolution NMR spectroscopy in another membrane-mimicking micellar environment and identified an alternative HER2 transmembrane domain dimerization coupled with self-association of membrane-embedded cytoplasmic juxtamembrane region. Such a dimerization mode appears to be capable of effectively inhibiting the receptor kinase activity. This finding refines the molecular mechanism regarding the signal propagation steps from the extracellular to cytoplasmic domains of HER/ErbB receptors.

    ID:1369