A5077254461- Photoreceptor and optogenetics research
- Advanced Fluorescence Microscopy Techniques
- Photosynthetic Processes and Mechanisms
- Metal-Catalyzed Oxygenation Mechanisms
- Spectroscopy and Quantum Chemical Studies
- Click Chemistry and Applications
- CO2 Reduction Techniques and Catalysts
- bioluminescence and chemiluminescence research
- Microbial metabolism and enzyme function
- Crystallization and Solubility Studies
- Metalloenzymes and iron-sulfur proteins
- Porphyrin Metabolism and Disorders
- X-ray Diffraction in Crystallography
- Molecular spectroscopy and chirality
- Photochromic and Fluorescence Chemistry
- Light effects on plants
- Protein Structure and Dynamics
- Electron Spin Resonance Studies
- RNA modifications and cancer
- Cellular Mechanics and Interactions
- Genetics, Bioinformatics, and Biomedical Research
- Synthesis and biological activity
- Nanowire Synthesis and Applications
- Carbohydrate Chemistry and Synthesis
- Microbial bioremediation and biosurfactants
Pennsylvania State University
2022-2024
Stanford University
2016-2023
National Taiwan University
2004-2015
National Institutes of Health
1981-1984
National Cancer Institute
1981-1984
Abstract Technologically critical rare-earth elements are notoriously difficult to separate, owing their subtle differences in ionic radius and coordination number 1–3 . The natural lanthanide-binding protein lanmodulin (LanM) 4,5 is a sustainable alternative conventional solvent-extraction-based separation 6 Here we characterize new LanM, from Hansschlegelia quercus ( Hans -LanM), with an oligomeric state sensitive radius, the lanthanum(III)-induced dimer being >100-fold tighter than...
Electrostatics guide chromophore twist Photoisomerization—the twisting of bonds in a molecule response to absorption light—is exploited biology sense light and can influence the photophysical properties fluorescent proteins used imaging applications. Romei et al. studied this behavior by introducing unnatural amino acids into photoswitchable green protein Dronpa2, thus systematically altering electronic (see Perspective Hu ). Crystal structures spectroscopic analyses series these variants...
Green fluorescent proteins (GFPs) have become indispensable imaging and optogenetic tools. Their absorption emission properties can be optimized for specific applications. Currently, no unified framework exists to comprehensively describe these photophysical properties, namely the maxima, Stokes shifts, vibronic progressions, extinction coefficients, Stark tuning rates, spontaneous especially one that includes effects of protein environment. In this work, we study correlations among from...
Abstract The photoisomerization reaction of a fluorescent protein chromophore occurs on the ultrafast timescale. structural dynamics that result from femtosecond optical excitation have contributions vibrational and electronic processes involve crossing through conical intersection. creation progression strongly depends molecular parameters. When using X-ray crystallography as probe dynamics, origin observed nuclear motions is not known. Now, high-resolution pump–probe reveals complex...
Important bioactive natural products, including prostaglandin H2 and artemisinin, contain reactive endoperoxides. Known enzymatic pathways for endoperoxide installation require multiple hydrogen-atom transfers (HATs). For example, iron(II)- 2-oxoglutarate-dependent verruculogen synthase (FtmOx1; EC 1.14.11.38) mediates HAT from aliphatic C21 of fumitremorgin B, capture O2 by the radical (C21•), addition peroxyl (C21-O-O•) to olefinic C27, resultant C26•. Recent studies proposed conflicting...
The neutral or A state of the green fluorescent protein (GFP) chromophore is a remarkable example photoacid naturally embedded in environment and accounts for large Stokes shift GFP response to near UV excitation. Its color tuning mechanism has been largely overlooked, as it less preferred imaging applications than redder anionic B state. Past studies, based on site-directed mutagenesis solvatochromism isolated chromophore, have concluded that its range much narrower counterpart. However, we...
The past decades have witnessed an explosion of de novo protein designs with a remarkable range scaffolds. It remains challenging, however, to design catalytic functions that are competitive naturally occurring counterparts as well biomimetic or nonbiological catalysts. Although directed evolution often offers efficient solutions, the fitness landscape opaque. Green fluorescent (GFP), which has revolutionized biological imaging and assays, is one most redesigned proteins. While not enzyme in...
Split GFPs have been widely applied for monitoring protein-protein interactions by expressing as two or more constituent parts linked to separate proteins that only fluoresce on complementing with one another. Although this complementation is typically irreversible, it has shown previously light accelerates dissociation of a noncovalently attached β-strand from circularly permuted split GFP, allowing the interaction be reversible. Reversible desirable, but photodissociation too low an...
N-Acetylnorloline synthase (LolO) is one of several iron(II)- and 2-oxoglutarate-dependent (Fe/2OG) oxygenases that catalyze sequential reactions different types in the biosynthesis valuable natural products. LolO hydroxylates C2 1-exo-acetamidopyrrolizidine before coupling C2-bonded oxygen to C7 form tricyclic loline core. Each reaction requires cleavage a C–H bond by an oxoiron(IV) (ferryl) intermediate; however, carbons are targeted, carbon radicals have fates. Prior studies indicated...
Significance Reaction centers (RCs) are critical to photosynthetic energy conversion. RCs in all characterized organisms contain two symmetrically arranged branches of chromophores and enable light-induced electron transfer with high yield. We fine-tune the properties a key bacterial RC symmetry-breaking tyrosine via its replacement noncanonical analogs determine kinetic outcomes. Results interpreted through energetic characterization made possible by resonance Stark spectroscopy. Analysis...
An aliphatic halogenase requires four substrates: 2-oxoglutarate (2OG), halide (Cl
Short hydrogen bonds, with heavy-atom distances less than 2.7 Å, are believed to exhibit proton delocalization, and their possible role in catalysis has been widely debated. While spectroscopic and/or structural methods usually employed study the degree of ambiguities still arise, no direct information on corresponding potential energy surface is obtained. Here, we apply an external electric field perturb short bond(s) within a collection green fluorescent protein S65T/H148D variants...
N-Acetylnorloline synthase (LolO) is one of several iron(II)- and 2-oxoglutarate-dependent (Fe/2OG) oxygenases that catalyze sequential reactions different types in biosynthetic pathways provide valuable natural products. LolO hydroxylates C2 1-exo-acetamidopyrrolizidine before coupling the C2-bonded oxygen to C7 form tricyclic (nor)loline core. Each reaction requires abstraction hydrogen (H•) from carbon by an oxoiron(IV) (ferryl) intermediate, but sites are targeted, radicals have fates....
Elucidating details of biology’s selective uptake and trafficking rare earth elements, particularly the lanthanides, has potential to inspire sustainable biomolecular separations these essential metals for myriad modern technologies. Here, we biochemically structurally characterize Methylobacterium ( Methylorubrum ) extorquens LanD, a periplasmic protein from bacterial gene cluster lanthanide uptake. This provides only four ligands at its surface-exposed lanthanide-binding site, allowing...
Green fluorescent protein (GFPs) have become indispensable imaging and optogenetic tools. Their absorption emission properties can be optimized for specific applications. Currently, no unified framework exists to comprehensively describe these photophysical properties, namely the maxima, Stokes shifts, vibronic progressions, extinction coefficients, Stark tuning rates, spontaneous especially one that includes effects of environment. In this work, we study correlations among from...
Abstract Many transcribed RNAs are non-coding RNAs, including microRNAs (miRNAs), which bind to complementary sequences on messenger regulate the translation efficacy. Therefore, identifying miRNAs expressed in cells/organisms aids understanding genetic control cells/organisms. In this report, we determined binding of oligonucleotides a receptor-modified silicon nanowire field-effect transistor (SiNW-FET) by monitoring changes conductance SiNW-FET. We first modified SiNW-FET with DNA probe...
Green fluorescent protein (GFPs) have become indispensable imaging and optogenetic tools. Their absorption emission properties can be optimized for specific applications. Currently, no unified framework exists to comprehensively describe these photophysical properties, namely the maxima, Stokes shifts, vibronic progressions, extinction coefficients, Stark tuning rates, spontaneous especially one that includes effects of environment. In this work, we study correlations among from...
An aliphatic halogenase requires four substrates: 2-oxoglutarate (2OG), halide (Cl - or Br ), the halogenation target ("prime substrate"), and dioxygen. In well-studied cases, three non-gaseous substrates must bind to activate enzyme's Fe(II) cofactor for efficient capture of O 2 . Halide, 2OG, (lastly) all coordinate directly initiate its conversion a cis -halo-oxo-iron(IV) (haloferryl) complex, which abstracts hydrogen (H•) from non-coordinating prime substrate enable radicaloid...
Photosynthetic reaction centers (RCs) from Rhodobacter sphaeroides were engineered to vary the electronic properties of a key tyrosine close an essential electron transfer component (M210) via its replacement with site-specific genetically encoded noncanonical amino acid analogs. High fidelity incorporation was verified mass spectrometry and x-ray crystallography demonstrated that RC variants exhibit no significant structural alterations relative wild-type. Ultrafast transient absorption...