The Role of Conformational Changes in Molecular Recognition

2016 ◽  
Vol 120 (9) ◽  
pp. 2138-2144 ◽  
Author(s):  
Mazen Ahmad ◽  
Volkhard Helms ◽  
Olga V. Kalinina ◽  
Thomas Lengauer
Author(s):  
Hideo Hayashi ◽  
Yoshikazu Hirai ◽  
John T. Penniston

Spectrin is a membrane associated protein most of which properties have been tentatively elucidated. A main role of the protein has been assumed to give a supporting structure to inside of the membrane. As reported previously, however, the isolated spectrin molecule underwent self assemble to form such as fibrous, meshwork, dispersed or aggregated arrangements depending upon the buffer suspended and was suggested to play an active role in the membrane conformational changes. In this study, the role of spectrin and actin was examined in terms of the molecular arrangements on the erythrocyte membrane surface with correlation to the functional states of the ghosts.Human erythrocyte ghosts were prepared from either freshly drawn or stocked bank blood by the method of Dodge et al with a slight modification as described before. Anti-spectrin antibody was raised against rabbit by injection of purified spectrin and partially purified.


Author(s):  
Lev Levintov ◽  
Harish Vashisth

Ribonucleic acid (RNA) molecules are known to undergo conformational changes in response to various environmental stimuli including temperature, pH, and ligands. In particular, viral RNA molecules are a key example...


Biochemistry ◽  
2005 ◽  
Vol 44 (50) ◽  
pp. 16624-16632 ◽  
Author(s):  
Silvia Lecchi ◽  
Kenneth E. Allen ◽  
Juan Pablo Pardo ◽  
A. Brett Mason ◽  
Carolyn W. Slayman

2008 ◽  
Vol 23 (7) ◽  
pp. 1101-1108 ◽  
Author(s):  
Laura Guardia ◽  
Rosana Badía-Laíño ◽  
Marta Elena Díaz-García ◽  
Conchi O. Ania ◽  
José B. Parra

Author(s):  
Zhao Yang ◽  
Fan Yang ◽  
Anthony Nguen ◽  
Chuan Liu ◽  
Amy Lin ◽  
...  

2021 ◽  
Author(s):  
Janelle Chuah ◽  
Tifffany Thibaudeau ◽  
David Smith

Abstract Impairment of proteasomal function has been implicated in neurodegenerative diseases, justifying the need to understand how the proteasome is activated for protein degradation. Here, using biochemical and structural (cryo-EM) strategies in both archaeal and mammalian proteasomes, we further determine the HbYX(-motif)-dependent mechanism of proteasomal activation used by multiple proteasome-activating complexes including the 19S Particle. We identify multiple proteasome α subunit residues involved in HbYX-dependent activation, a point mutation that activates the proteasome by partially mimicking a HbYX-bound state, and conformational changes involved in gate-opening with a 2.0A structure. Through an iterative process of peptide synthesis, we successfully design a HbYX-like dipeptide mimetic as a robust tool to elucidate how the motif autonomously activates the proteasome. The mimetic induces near complete gate-opening at saturating concentration, activating mammalian proteasomal degradation of peptides and proteins. Findings using our peptide mimetic suggest the HbYX-dependent mechanism requires cooperative binding in at least two intersubunit pockets of the α ring. Collectively, the results presented here unambiguously demonstrate the lone role of the HbYX tyrosine in the allosteric mechanism of proteasome activation and offer proof of concept for the robust potential of HbYX-like small molecules to activate the proteasome.


2019 ◽  
Author(s):  
Minjoo Kim ◽  
Nicholas J. Sisco ◽  
Jacob K. Hilton ◽  
Camila M. Montano ◽  
Manuel A. Castro ◽  
...  

AbstractSensing and responding to temperature is crucial in biology. The TRPV1 ion channel is a well-studied heat-sensing receptor that is also activated by vanilloid compounds including capsaicin. Despite significant interest, the molecular underpinnings of thermosensing have remained elusive. The TRPV1 S1-S4 membrane domain couples chemical ligand binding to the pore domain during channel gating. However, the role of the S1-S4 domain in thermosensing is unclear. Evaluation of the isolated human TRPV1 S1-S4 domain by solution NMR, Far-UV CD, and intrinsic fluorescence shows that this domain undergoes a non-denaturing temperature-dependent transition with a high thermosensitivity. Further NMR characterization of the temperature-dependent conformational changes suggests the contribution of the S1-S4 domain to thermosensing shares features with known coupling mechanisms between this domain with ligand and pH activation. Taken together, this study shows that the TRPV1 S1-S4 domain contributes to TRPV1 temperature-dependent activation.


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