scholarly journals Discriminating changes in protein structure using PTAD conjugation to tyrosine

2020 ◽  
Author(s):  
Mahta Moinpour ◽  
Natalie K. Barker ◽  
Lindsay E. Guzman ◽  
John C. Jewett ◽  
Paul R. Langlais ◽  
...  

ABSTRACTChemical modification of proteins has been crucial in engineering protein-based therapies, targeted biopharmaceutics, molecular probes, and biomaterials. Here, we explore the use of a conjugation-based approach to sense alternative conformational states in proteins. Tyrosine has both hydrophobic and hydrophilic qualities, thus allowing it to be positioned at protein surfaces, or binding interfaces, or to be buried within a protein. Tyrosine can be conjugated with 4-phenyl-3H-1,2,4-triazole-3,5(4H)-dione (PTAD). We hypothesized that individual protein conformations could be distinguished by labeling tyrosine residues in the protein with PTAD. We conjugated tyrosine residues in a well-folded protein, bovine serum albumin (BSA), and quantified labeled tyrosine with LC-MS/MS. We applied this approach to alternative conformations of BSA produced in the presence of urea. The amount of PTAD labeling was found to relate to the depth of each tyrosine relative to the protein surface. This study demonstrates a new use of tyrosine conjugation using PTAD as an analytic tool able to distinguish the conformational states of a protein.

2010 ◽  
Vol 5 (4) ◽  
pp. 182-185
Author(s):  
Angelina V. Kapralova ◽  
Aleksandr S. Pogodin

We investigated the influence of THz laser radiation of frequencies of 1.15 THz and 3.68 THz and radiation power of about 10 Mw on protein (bovine serum albumin). Using UV spectrophotometry, we revealed increase in the optical density of irradiated samples of bovine serum albumin at the characteristic absorption bands, which is evidence of conformation changes in protein molecules


2003 ◽  
Vol 85 (6) ◽  
pp. 3943-3950 ◽  
Author(s):  
Geoffrey J. Brownsey ◽  
Timothy R. Noel ◽  
Roger Parker ◽  
Stephen G. Ring

Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 343
Author(s):  
Pavlína Andrýsková ◽  
Karolína Machalová Šišková ◽  
Šárka Michetschlägerová ◽  
Klára Jiráková ◽  
Martin Kubala ◽  
...  

Fluorescent gold nanoclusters (AuNCs) are envisaged as a novel type of fluorophores. This work reports on the first comparative study investigating the effect of presence/absence/abundance of fatty acids (namely palmitic acid, PA) or other substances (like glycoproteins and globulins) in the protein (bovine serum albumin, BSA) on synthesis and properties of the final AuNCs. The most popular template (BSA) and microwave (MW)-assisted synthesis of AuNCs have been intentionally chosen. Our results clearly demonstrate that the fluorescent characteristics (i.e., fluorescence lifetime and quantum yield) are affected by the fatty acids and/or other substances. Importantly, the as-prepared AuNCs are biocompatible, as determined by Alamar Blue assay performed on Hep G2 cell line.


2020 ◽  
Vol 22 (9) ◽  
pp. 5264-5271
Author(s):  
Mohammadhasan Hedayati ◽  
Matt J. Kipper ◽  
Diego Krapf

Single-molecule tracking reveals the protein bovine serum albumin exhibits anomalous kinetics with a heavy-tailed dwell time distribution on PEG surfaces. This effect is shown to be caused by the ability of the protein to oligomerize in solution.


1984 ◽  
Vol 222 (2) ◽  
pp. 407-411 ◽  
Author(s):  
S Ito ◽  
T Kato ◽  
K Shinpo ◽  
K Fujita

A simple and rapid method was developed for the determination of 3,4-dihydroxyphenylalanine (dopa) and 5-S-cysteinyl-3,4-dihydroxyphenylalanine (5-S-cysteinyldopa) in proteins with the use of high-pressure liquid chromatography. With this method, it is demonstrated that mushroom tyrosinase can catalyse hydroxylation of tyrosine residues in proteins to dopa and subsequent oxidation to dopaquinone residues. The dopaquinone residues in proteins combine with cysteine residues to form 5-S-cysteinyldopa in bovine serum albumin and yeast alcohol dehydrogenase, whereas dopa is the major product in bovine insulin, which lacks cysteine residues.


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