Binding chemistry and molecular heterogeneity of neurotensin binding protein(s)/receptor in adult chicken tissues.

dc.contributor.authorMitra, Sankar P
dc.date.accessioned2014-02-05T04:13:28Z
dc.date.available2014-02-05T04:13:28Z
dc.date.issued2013-12
dc.description.abstractThe study focuses on the importance of Tyr11 amino acid (AA) and subsequent stereochemistry involved in the binding process of neurotensin (NT) with its receptor (NTR)/binding protein(s) as well as the size heterogeneity. Using the binding of 125I-NT with several chicken tissues, it is identified that one of the crucial factors behind all high affinity (Kd ~10 pM) interactions is due to phenolic-OH (Φ-OH) at the para (p) position of Tyr11 within RRPYIL-CO2H (NT8-13) sequence. Replacing the p-OH only in Tyr11 by substituting with p-Cl, p-F and p-NH2 results in significant change of the binding affinity (Kd); p-OH ≈ p-NH2 (~10 pM), p-Cl (~100 pM), p-F (~120 pM). Interestingly, p-NH2 equals to p-OH displaying the highest affinity. Experiments conducted by binding several of the 125I-azido–NT analogs having azido group attached at different positions within the NT molecule have further confirmed the necessity of RRPYIL sequence for high affinity ligand-receptor interaction. The role of Tryp11 in place of Tyr11 in addition to the results above establishes a significant possibility of H–bonding occurring between p-OH of NT and NTR inside the docking space. Photo labeling of the liver tissue by substituted 125I-Y3-azido-NT analogs shows several specifically labeled bands with considerable range of molecular weight (Mr ~90-30 kDa) variations. These results indicate the existence of molecular heterogeneity concerning the sizes of NTR or else any NT binding proteins in the avian tissues. Further, the study has revealed that besides liver, several other chicken tissues also express similar specific high affinity binding (Kd ~20 pM) with varying capacities (Bmax). The order for Bmax is: liver (1.2 pMol/mg) gall bladder (1.03 pMol/mg) > spleen (0.43 pMol/mg) > brain (0.3 pMol/mg) > colon lung (0.15 pMol/mg). In all cases, the binding was reduced by GTPgS (ED50 ~ 0.05 nM), NEM (ED50 ~ 0.50 mM) and NaCl (ED50 ~30 mM), indicating the existence of NTR identical to the mammalian type-1.en_US
dc.identifier.citationMitra Sankar P. Binding chemistry and molecular heterogeneity of neurotensin binding protein(s)/receptor in adult chicken tissues. Indian Journal of Biochemistry & Biophysics. 2013 Dec; 50(6): 511-520.en_US
dc.identifier.urihttps://imsear.searo.who.int/handle/123456789/150265
dc.language.isoenen_US
dc.source.urihttps://nopr.niscair.res.in/handle/123456789/25165en_US
dc.subjectNeurotensinen_US
dc.subjectNeurotensin receptoren_US
dc.subjectGuanosine 5-O–[γ-thio] triphosphateen_US
dc.subjectN-ethylmaleimideen_US
dc.subject125I-Neurotensin bindingen_US
dc.subjectPhotoaffinity labelingen_US
dc.subjectPhotoactivatable azido analoguesen_US
dc.subjectG-protein coupled receptoren_US
dc.subjectAntagonist SR48692en_US
dc.subjectLevocabastineen_US
dc.subjectImmune precipitationen_US
dc.subject.meshAmino Acid Sequence
dc.subject.meshAmino Acid Substitution
dc.subject.meshAnimals
dc.subject.meshAzides --chemistry
dc.subject.meshBinding, Competitive
dc.subject.meshCell Membrane --metabolism
dc.subject.meshChickens
dc.subject.meshEthylmaleimide --pharmacology
dc.subject.meshFemale
dc.subject.meshGuanosine 5'-O-(3-Thiotriphosphate)/ --pharmacology
dc.subject.meshLiver --cytology
dc.subject.meshMale
dc.subject.meshMolecular Weight
dc.subject.meshNeurotensin --chemistry
dc.subject.meshNeurotensin --genetics
dc.subject.meshNeurotensin --metabolism
dc.subject.meshProtein Binding --drug effects
dc.subject.meshPyrazoles --pharmacology
dc.subject.meshQuinolines --pharmacology
dc.subject.meshReceptors, Neurotensin --antagonists & inhibitors
dc.subject.meshReceptors, Neurotensin --chemistry
dc.subject.meshReceptors, Neurotensin --metabolism
dc.subject.meshSodium Chloride --pharmacology
dc.subject.meshStereoisomerism
dc.subject.meshTyrosine
dc.titleBinding chemistry and molecular heterogeneity of neurotensin binding protein(s)/receptor in adult chicken tissues.en_US
dc.typeArticleen_US
Files
Original bundle
Now showing 1 - 1 of 1
Loading...
Thumbnail Image
Name:
ijbb2013v50n6p511.pdf
Size:
398.08 KB
Format:
Adobe Portable Document Format
Description:
Journal article
License bundle
Now showing 1 - 1 of 1
No Thumbnail Available
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description: