Allovalency observed by transferred‐NOE: Interactions of sulfated tyrosine residues in the N‐terminal segment of CCR5 with the CCL5 chemokine

FEBS Journal ◽  
2020 ◽  
Author(s):  
Naama Kessler ◽  
Sabine R. Akabayov ◽  
Adi Moseri ◽  
Leah S. Cohen ◽  
Damir Sakhapov ◽  
...  
Keyword(s):  
Terminal Segment ◽  
Tyrosine Residues ◽  
Transferred Noe

Binding of glucagon to lipid bilayers

1990 ◽  
Vol 68 (1) ◽  
pp. 284-291 ◽  
Author(s):  
Raymond P. Oomen ◽  
Harvey Kaplan
Keyword(s):  
Lipid Bilayers ◽  
Functional Groups ◽  
Marked Decrease ◽  
Terminal Segment ◽  
Crystallographic Structure ◽  
Amino Groups ◽  
X Ray ◽  
Tyrosine Residues ◽  
Amino Terminal

At physiological pH and temperature, glucagon binds to liposomes composed of egg phosphatidylcholine and cholesterol (2:1 mol/mol) in a highly specific manner. The chemical reactivities of the functional groups were determined over the concentration range of 1.0 × 10−6 – 3.0 × 10−8 M by the method of competitive labelling with 1-fluoro-2,4-dinitrobenzene as the labelling reagent. At concentrations above 3 × 10−7 M, the amino terminal histidine and the two tyrosine residues showed a marked decrease in reactivity in the presence of liposomes, but the reactivity of the Lys-12 Nε-amino group was unaltered. At lower concentrations the Lys-12 reactivity also decreased markedly, owing to a change in the environment of this group. These results indicated that two different forms of glucagon existed over the concentration range studied. Both in the absence and presence of liposomes the Lys-12 Nε-amino groups showed a transition in reactivity at 1.8 × 10−7 M. In the presence of liposomes the other functional groups also showed a transition in reactivity at 2 × 10−7 M but the change was much smaller. The pattern of reactivities were consistent with the X-ray crystallographic structure of the type 2 glucagon trimer being the predominant species at 10−6 M, with free monomeric glucagon occurring at 3 × 10−8 M. A trimerization constant of 4 × 1013 M−2 at pH 7.5 and 37 °C was determined. It is concluded that trimeric glucagon binds to phosphatidylcholine–cholesterol bilayers primarily with the amino-terminal segment of the polypeptide chain and that additional regions of the molecule are involved in binding of the free monomeric unit.Key words: glucagon, liposomes, binding, reactivity.

scholarly journals Structure of spastin bound to a glutamate-rich peptide implies a hand-over-hand mechanism of substrate translocation

2019 ◽  
Vol 295 (2) ◽  
pp. 435-443 ◽  
Author(s):  
Han Han ◽  
Heidi L. Schubert ◽  
John McCullough ◽  
Nicole Monroe ◽  
Michael D. Purdy ◽  
...  
Keyword(s):  
Critical Role ◽  
Terminal Segment ◽  
The Other ◽  
Eukaryotic Cells ◽  
Peptide Substrate ◽  
Family Function ◽  
Aaa Atpase ◽  
Protein Substrates ◽  
Tyrosine Residues ◽  
Microtubule Severing

Many members of the AAA+ ATPase family function as hexamers that unfold their protein substrates. These AAA unfoldases include spastin, which plays a critical role in the architecture of eukaryotic cells by driving the remodeling and severing of microtubules, which are cytoskeletal polymers of tubulin subunits. Here, we demonstrate that a human spastin binds weakly to unmodified peptides from the C-terminal segment of human tubulin α1A/B. A peptide comprising alternating glutamate and tyrosine residues binds more tightly, which is consistent with the known importance of glutamylation for spastin microtubule severing activity. A cryo-EM structure of the spastin-peptide complex at 4.2 Å resolution revealed an asymmetric hexamer in which five spastin subunits adopt a helical, spiral staircase configuration that binds the peptide within the central pore, whereas the sixth subunit of the hexamer is displaced from the peptide/substrate, as if transitioning from one end of the helix to the other. This configuration differs from a recently published structure of spastin from Drosophila melanogaster, which forms a six-subunit spiral without a transitioning subunit. Our structure resembles other recently reported AAA unfoldases, including the meiotic clade relative Vps4, and supports a model in which spastin utilizes a hand-over-hand mechanism of tubulin translocation and microtubule remodeling.

Characterization of drug interaction of pore-exposed tyrosine residues

2013 ◽  
Vol 1 (Suppl. 1) ◽  
pp. A3.15
Author(s):  
Yaprak Dönmez Çakıl
Keyword(s):  
Drug Interaction ◽  
Tyrosine Residues

Prediction of Nitration Sites Based on FCBF Method and Stacking Ensemble Model

2021 ◽  
Vol 18 ◽  
Author(s):  
Min Liu ◽  
Lu Zhang ◽  
Xinyi Qin ◽  
Tao Huang ◽  
Ziwei Xu ◽  
...  
Keyword(s):  
Prediction Model ◽  
Protein Sequence ◽  
Cross Validation ◽  
Transplant Rejection ◽  
Sampling Technique ◽  
Single Type ◽  
Post Translational Modification ◽  
Tyrosine Residues ◽  
Under Sampling ◽  
Fusion Features

Background: Nitration is one of the important Post-Translational Modification (PTM) occurring on the tyrosine residues of proteins. The occurrence of protein tyrosine nitration under disease conditions is inevitable and represents a shift from the signal transducing physiological actions of -NO to oxidative and potentially pathogenic pathways. Abnormal protein nitration modification can lead to serious human diseases, including neurodegenerative diseases, acute respiratory distress, organ transplant rejection and lung cancer. Objective: It is necessary and important to identify the nitration sites in protein sequences. Predicting that which tyrosine residues in the protein sequence are nitrated and which are not is of great significance for the study of nitration mechanism and related diseases. Methods: In this study, a prediction model of nitration sites based on the over-under sampling strategy and the FCBF method was proposed by stacking ensemble learning and fusing multiple features. Firstly, the protein sequence sample was encoded by 2701-dimensional fusion features (PseAAC, PSSM, AAIndex, CKSAAP, Disorder). Secondly, the ranked feature set was generated by the FCBF method according to the symmetric uncertainty metric. Thirdly, in the process of model training, use the over- and under- sampling technique was used to tackle the imbalanced dataset. Finally, the Incremental Feature Selection (IFS) method was adopted to extract an optimal classifier based on 10-fold cross-validation. Results and Conclusion: Results show that the model has significant performance advantages in indicators such as MCC, Recall and F1-score, no matter in what way the comparison was conducted with other classifiers on the independent test set, or made by cross-validation with single-type feature or with fusion-features on the training set. By integrating the FCBF feature ranking methods, over- and under- sampling technique and a stacking model composed of multiple base classifiers, an effective prediction model for nitration PTM sites was build, which can achieve a better recall rate when the ratio of positive and negative samples is highly imbalanced.

Ca2+-Myristoyl Switch in Neuronal Calcium Sensor-1: A Role of C-Terminal Segment

2015 ◽  
Vol 14 (4) ◽  
pp. 437-451 ◽  
Author(s):  
Viktoriia Baksheeva ◽  
Aliya Nazipova ◽  
Dmitry Zinchenko ◽  
Marina Serebryakova ◽  
Ivan Senin ◽  
...  
Keyword(s):  
Terminal Segment ◽  
Calcium Sensor ◽  
Neuronal Calcium Sensor ◽  
Myristoyl Switch

scholarly journals Identification of the insulin receptor tyrosine residues undergoing insulin-stimulated phosphorylation in intact rat hepatoma cells.

1988 ◽  
Vol 263 (1) ◽  
pp. 350-359 ◽  
Author(s):  
H E Tornqvist ◽  
J R Gunsalus ◽  
R A Nemenoff ◽  
A R Frackelton ◽  
M W Pierce ◽  
...  
Keyword(s):  
Insulin Receptor ◽  
Hepatoma Cells ◽  
Tyrosine Residues ◽  
Rat Hepatoma ◽  
Rat Hepatoma Cells
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