Please use this identifier to cite or link to this item: https://ir.swu.ac.th/jspui/handle/123456789/12771
ชื่อเรื่อง: Tuning the chain length of new pyrene derivatives for site-selective photocleavage of avidin
ผู้แต่ง: Yenjai S.
Kumar C.V.
Kuno M.
Liwporncharoenvong T.
Samosorn S.
Buranaprapuk A.
Keywords: avidin
biotin
pyrene derivative
avidin
cobalt
cobalt ammonium complex
protein binding
pyrene derivative
absorption spectroscopy
Article
binding affinity
binding site
chemical structure
controlled study
enzyme denaturation
hydrogen bond
hydrophilicity
molecular docking
photochemistry
priority journal
protein cleavage
sequence analysis
spectrofluorometry
amino acid sequence
chemistry
kinetics
light
metabolism
photolysis
protein tertiary structure
radiation response
synthesis
Amino Acid Sequence
Avidin
Binding Sites
Cobalt
Hydrogen Bonding
Kinetics
Light
Molecular Docking Simulation
Photolysis
Protein Binding
Protein Structure, Tertiary
Pyrenes
Spectrometry, Fluorescence
วันที่เผยแพร่: 2018
บทคัดย่อ: Rational design of photoreagents with systematic modifications of their structures can provide valuable information for a better understanding of the protein photocleavage mechanism by these reagents. Variation of the length of the linker connecting the photoactive moiety with the protein anchoring-group allowed us to investigate the control of the protein photocleavage site. A series of new photochemical reagents (PMA-1A, PMA-2A and PMA-3A) with increasing chain lengths is examined in the current study. Using avidin as a model system, we examined the interaction of these probes by UV–Vis, fluorescence spectroscopic methods, photocleavage and computational docking studies. Hypochromism of the absorption spectrum was observed for the binding of these new photochemical reagents with estimated binding constants (Kb) of 6.2 × 105, 6.7 × 105 and 4.6 × 105 M−1, respectively. No significant changes of Stern-Volmer quenching constant (Ksv) with Co(NH3)6Cl3 has been noted and the data indicated that the probes bind near the surface of the protein with sufficient exposure to the solvent. Photoexcitation of the probe-avidin complex, in the presence of Co(NH3)6Cl3, resulted in protein fragmentation, and the cleavage yield decreased with the increase in the linker length, and paralleled with the observed Ksv values. Amino acid sequencing of the photofragments indicated that avidin is cleaved between Thr77 and Val78, as a major cleavage site for all the three photoreagents. This site is proximate to the biotin binding site on avidin, and molecular docking studies indicated that the H-bonding interactions between the polar end-group of the photoreagents and hydrophilic amino acids of avidin were important in positioning the reagent on the protein. The major cleavage site, at residues 77–78, was within 5 Å of the pyrenyl moiety of the probe, and hence, molecular tuning of the linker provided a simple approach to position the photoreagent along the potential photocleavage site. © 2018
URI: https://ir.swu.ac.th/jspui/handle/123456789/12771
https://www.scopus.com/inward/record.uri?eid=2-s2.0-85049478108&doi=10.1016%2fj.jphotobiol.2018.07.001&partnerID=40&md5=49dbdf1e7c805a006741798a29aa4070
ISSN: 10111344
Appears in Collections:Scopus 1983-2021

Files in This Item:
There are no files associated with this item.


Items in SWU repository are protected by copyright, with all rights reserved, unless otherwise indicated.