scholarly journals The inner mechanics of Rhodopsin Guanylyl Cyclase during 2cGMP-formation revealed by real-time FTIR spectroscopy

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Paul Fischer ◽  
Shatanik Mukherjee ◽  
Enrico Peter ◽  
Matthias Broser ◽  
Franz Bartl ◽  
...  
Keyword(s):  
Enzyme Activity ◽  
Real Time ◽  
Protein Interactions ◽  
Uv Light ◽  
Spectroscopic Characterization ◽  
Binding Pocket ◽  
Molecular Signaling ◽  
Protein Protein Interactions ◽  
Regulatory Influence ◽  
Truncated Variants

Enzymerhodopsins represent a recently discovered class of rhodopsins which includes histidine kinase rhodopsin, rhodopsin phosphodiesterases and rhodopsin guanylyl cyclases (RGCs). The regulatory influence of the rhodopsin domain on the enzyme activity is only partially understood and holds the key for a deeper understanding of intra-molecular signaling pathways. Here we present a UV-Vis and FTIR study about the light-induced dynamics of a RGC from the fungus Catenaria anguillulae, which provides insights into the catalytic process. After the spectroscopic characterization of the late rhodopsin photoproducts, we analyzed truncated variants and revealed the involvement of the cytosolic N-terminus in the structural rearrangements upon photo-activation of the protein. We tracked the catalytic reaction of RGC and the free GC domain independently by UV-light induced release of GTP from the photolabile NPE-GTP substrate. Our results show substrate binding to the dark-adapted RGC and GC alike and reveal differences between the constructs attributable to the regulatory influence of the rhodopsin on the conformation of the binding pocket. By monitoring the phosphate rearrangement during cGMP and pyrophosphate formation in light-activated RGC, we were able to confirm the M state as the active state of the protein. The described setup and experimental design enable real-time monitoring of substrate turnover in light-activated enzymes on a molecular scale, thus opening the pathway to a deeper understanding of enzyme activity and protein-protein interactions.

scholarly journals EndoBind detects endogenous protein-protein interactions in real time

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Anke Bill ◽  
Sheryll Espinola ◽  
Daniel Guthy ◽  
Jacob R. Haling ◽  
Mylene Lanter ◽  
...  
Keyword(s):  
Real Time ◽  
High Throughput ◽  
Protein Interactions ◽  
Continuous Monitoring ◽  
Protein Protein Interactions ◽  
Dimer Formation ◽  
Endogenous Protein ◽  
Extended Duration ◽  
Substrate Addition

AbstractWe present two high-throughput compatible methods to detect the interaction of ectopically expressed (RT-Bind) or endogenously tagged (EndoBind) proteins of interest. Both approaches provide temporal evaluation of dimer formation over an extended duration. Using examples of the Nrf2-KEAP1 and the CRAF-KRAS-G12V interaction, we demonstrate that our method allows for the detection of signal for more than 2 days after substrate addition, allowing for continuous monitoring of endogenous protein-protein interactions in real time.

Protein-Protein Interactions (PPIs) as an Alternative to Targeting the ATP Binding Site of Kinase

2016 ◽  
pp. 249-277
Author(s):  
Sailu Sarvagalla ◽  
Mohane Selvaraj Coumar
Keyword(s):  
Protein Interactions ◽  
In Silico ◽  
Rational Design ◽  
Kinase Activity ◽  
Hot Spot ◽  
Binding Pocket ◽  
Atp Binding ◽  
Protein Protein Interactions ◽  
Structure Based Drug Design ◽  
Atp Binding Site

Most of the developed kinase inhibitor drugs are ATP competitive and suffer from drawbacks such as off-target kinase activity, development of resistance due to mutation in the ATP binding pocket and unfavorable intellectual property situations. Besides the ATP binding pocket, protein kinases have binding sites that are involved in Protein-Protein Interactions (PPIs); these PPIs directly or indirectly regulate the protein kinase activity. Of recent, small molecule inhibitors of PPIs are emerging as an alternative to ATP competitive agents. Rational design of inhibitors for kinase PPIs could be carried out using molecular modeling techniques. In silico tools available for the prediction of hot spot residues and cavities at the PPI sites and the means to utilize this information for the identification of inhibitors are discussed. Moreover, in silico studies to target the Aurora B-INCENP PPI sites are discussed in context. Overall, this chapter provides detailed in silico strategies that are available to the researchers for carrying out structure-based drug design of PPI inhibitors.

scholarly journals Mechanism of the G-protein mimetic nanobody binding to a muscarinic G-protein-coupled receptor

2018 ◽  
Vol 115 (12) ◽  
pp. 3036-3041 ◽  
Author(s):  
Yinglong Miao ◽  
J. Andrew McCammon
Keyword(s):  
Protein Binding ◽  
G Protein ◽  
Protein Interactions ◽  
Intracellular Signaling ◽  
Md Simulations ◽  
Binding Pocket ◽  
Signaling Proteins ◽  
Protein Protein Interactions ◽  
Intracellular Loops ◽  
G Protein Coupled

Protein–protein binding is key in cellular signaling processes. Molecular dynamics (MD) simulations of protein–protein binding, however, are challenging due to limited timescales. In particular, binding of the medically important G-protein-coupled receptors (GPCRs) with intracellular signaling proteins has not been simulated with MD to date. Here, we report a successful simulation of the binding of a G-protein mimetic nanobody to the M2 muscarinic GPCR using the robust Gaussian accelerated MD (GaMD) method. Through long-timescale GaMD simulations over 4,500 ns, the nanobody was observed to bind the receptor intracellular G-protein-coupling site, with a minimum rmsd of 2.48 Å in the nanobody core domain compared with the X-ray structure. Binding of the nanobody allosterically closed the orthosteric ligand-binding pocket, being consistent with the recent experimental finding. In the absence of nanobody binding, the receptor orthosteric pocket sampled open and fully open conformations. The GaMD simulations revealed two low-energy intermediate states during nanobody binding to the M2 receptor. The flexible receptor intracellular loops contribute remarkable electrostatic, polar, and hydrophobic residue interactions in recognition and binding of the nanobody. These simulations provided important insights into the mechanism of GPCR–nanobody binding and demonstrated the applicability of GaMD in modeling dynamic protein–protein interactions.

Pseudokinase drug intervention: a potentially poisoned chalice

2013 ◽  
Vol 41 (4) ◽  
pp. 1083-1088 ◽  
Author(s):  
Jeroen Claus ◽  
Angus J.M. Cameron ◽  
Peter J. Parker
Keyword(s):  
Protein Interactions ◽  
Drug Targets ◽  
Binding Pocket ◽  
Atp Binding ◽  
Potential Drug ◽  
Protein Protein Interactions ◽  
Drug Intervention ◽  
Potential Impact ◽  
Potential Drug Targets ◽  
Selection Of

Pseudokinases, the catalytically impaired component of the kinome, have recently been found to share more properties with active kinases than previously thought. In many pseudokinases, ATP binding and even some activity is preserved, highlighting these proteins as potential drug targets. In both active kinases and pseudokinases, binding of ATP or drugs in the nucleotide-binding pocket can stabilize specific conformations required for activity and protein–protein interactions. We discuss the implications of locking particular conformations in a selection of (pseudo)kinases and the dual potential impact on the druggability of these proteins.

scholarly journals QCM Biosensor Based on Polydopamine Surface for Real-Time Analysis of the Binding Kinetics of Protein-Protein Interactions

Polymers ◽  
2017 ◽  
Vol 9 (12) ◽  
pp. 482 ◽  
Author(s):  
Chunli Wu ◽  
Xueming Li ◽  
Siyu Song ◽  
Yuxin Pei ◽  
Lili Guo ◽  
...  
Keyword(s):  
Real Time ◽  
Protein Interactions ◽  
Binding Kinetics ◽  
Protein Protein Interactions ◽  
Time Analysis ◽  
Real Time Analysis ◽  
Kinetics Of

scholarly journals Positive and Negative Regulation of Poly(A) Nuclease

2004 ◽  
Vol 24 (12) ◽  
pp. 5521-5533 ◽  
Author(s):  
David A. Mangus ◽  
Matthew C. Evans ◽  
Nathan S. Agrin ◽  
Mandy Smith ◽  
Preetam Gongidi ◽  
...  
Keyword(s):  
Amino Acids ◽  
Amino Acid ◽  
Protein Interactions ◽  
Binding Pocket ◽  
Negative Regulation ◽  
Single Amino Acid ◽  
Carboxy Terminus ◽  
Protein Protein Interactions ◽  
C Terminus

ABSTRACT PAN, a yeast poly(A) nuclease, plays an important nuclear role in the posttranscriptional maturation of mRNA poly(A) tails. The activity of this enzyme is dependent on its Pan2p and Pan3p subunits, as well as the presence of poly(A)-binding protein (Pab1p). We have identified and characterized the associated network of factors controlling the maturation of mRNA poly(A) tails in yeast and defined its relevant protein-protein interactions. Pan3p, a positive regulator of PAN activity, interacts with Pab1p, thus providing substrate specificity for this nuclease. Pab1p also regulates poly(A) tail trimming by interacting with Pbp1p, a factor that appears to negatively regulate PAN. Pan3p and Pbp1p both interact with themselves and with the C terminus of Pab1p. However, the domains required for Pan3p and Pbp1p binding on Pab1p are distinct. Single amino acid changes that disrupt Pan3p interaction with Pab1p have been identified and define a binding pocket in helices 2 and 3 of Pab1p's carboxy terminus. The importance of these amino acids for Pab1p-Pan3p interaction, and poly(A) tail regulation, is underscored by experiments demonstrating that strains harboring substitutions in these residues accumulate mRNAs with long poly(A) tails in vivo.

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