Diphenanthrioctaphyrin(1.1.1.0.1.1.1.0): Conformational Switching Controls the Stereochemical Dynamics of the Topologically Chiral System

2019 ◽  
Vol 141 (14) ◽  
pp. 6060-6072 ◽  
Author(s):  
Bartosz Szyszko ◽  
Piotr J. Chmielewski ◽  
Monika Przewoźnik ◽  
Michał J. Białek ◽  
Kamil Kupietz ◽  
...  
2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Siddarth Chandrasekaran ◽  
Connor M. Schneps ◽  
Robert Dunleavy ◽  
Changfan Lin ◽  
Cristina C. DeOliveira ◽  
...  

AbstractLight-induction of an anionic semiquinone (SQ) flavin radical in Drosophila cryptochrome (dCRY) alters the dCRY conformation to promote binding and degradation of the circadian clock protein Timeless (TIM). Specific peptide ligation with sortase A attaches a nitroxide spin-probe to the dCRY C-terminal tail (CTT) while avoiding deleterious side reactions. Pulse dipolar electron-spin resonance spectroscopy from the CTT nitroxide to the SQ shows that flavin photoreduction shifts the CTT ~1 nm and increases its motion, without causing full displacement from the protein. dCRY engineered to form the neutral SQ serves as a dark-state proxy to reveal that the CTT remains docked when the flavin ring is reduced but uncharged. Substitutions of flavin-proximal His378 promote CTT undocking in the dark or diminish undocking in the light, consistent with molecular dynamics simulations and TIM degradation activity. The His378 variants inform on recognition motifs for dCRY cellular turnover and strategies for developing optogenetic tools.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ling Xin ◽  
Xiaoyang Duan ◽  
Na Liu

AbstractIn living organisms, proteins are organized prevalently through a self-association mechanism to form dimers and oligomers, which often confer new functions at the intermolecular interfaces. Despite the progress on DNA-assembled artificial systems, endeavors have been largely paid to achieve monomeric nanostructures that mimic motor proteins for a single type of motion. Here, we demonstrate a DNA-assembled building block with rotary and walking modules, which can introduce new motion through dimerization and oligomerization. The building block is a chiral system, comprising two interacting gold nanorods to perform rotation and walking, respectively. Through dimerization, two building blocks can form a dimer to yield coordinated sliding. Further oligomerization leads to higher-order structures, containing alternating rotation and sliding dimer interfaces to impose structural twisting. Our hierarchical assembly scheme offers a design blueprint to construct DNA-assembled advanced architectures with high degrees of freedom to tailor the optical responses and regulate multi-motion on the nanoscale.


Biochemistry ◽  
2020 ◽  
Vol 59 (28) ◽  
pp. 2592-2601 ◽  
Author(s):  
Itsuki Kobayashi ◽  
Hiroto Nakajima ◽  
Osamu Hisatomi

2003 ◽  
Vol 5 (8) ◽  
pp. 1265-1267 ◽  
Author(s):  
Ryu Yamasaki ◽  
Aya Tanatani ◽  
Isao Azumaya ◽  
Shoichi Saito ◽  
Kentaro Yamaguchi ◽  
...  

2013 ◽  
Vol 52 (39) ◽  
pp. 10237-10240 ◽  
Author(s):  
Joice Thomas ◽  
Gunter Reekmans ◽  
Peter Adriaensens ◽  
Luc Van Meervelt ◽  
Mario Smet ◽  
...  

2018 ◽  
Vol 114 (3) ◽  
pp. 405a
Author(s):  
Neeladri S. Roy ◽  
Peng Zhai ◽  
Xiaoying Jian ◽  
Lisa Jenkins ◽  
Ruibai Luo ◽  
...  

2019 ◽  
Vol 75 (a2) ◽  
pp. e479-e479
Author(s):  
Saber Mirzaei ◽  
Qadir Timerghazin ◽  
Sergey Lindeman

2019 ◽  
Author(s):  
Pezhman Mohammadi ◽  
A. Sesilja Aranko ◽  
Christopher P. Landowski ◽  
Olli Ikkala ◽  
Kristaps Jaudzems ◽  
...  

Silk and cellulose are biopolymers that show a high potential as future sustainable materials.They also have complementary properties, suitable for combination in composite materials where cellulose would form the reinforcing component and silk the tough matrix. Therein, a major challenge concerns balancing structure and properties in the assembly process. We used recombinant proteins with triblock architecture combining structurally modified spider silk with terminal cellulose affinity modules. Flow-alignment of cellulose nanofibrils and triblock protein allowed a continuous fiber production.The protein assembly involved phase separation into concentrated coacervates, with subsequent conformational switching from disordered structures to beta sheets. This gave the matrix a tough adhesiveness, forming a new composite material with high strength and stiffness combined with increased toughness. We show that versatile design possibilities in protein engineering enable new fully biological materials, and emphasize the key role of controlled assembly at multiple length scales for realization.<br>


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