Size and Shape Controlled Crystallization of Hemoglobin for Advanced Crystallography

Sato‐Tomita, Ayana; Shibayama, Naoya

doi:10.3390/cryst7090282

Cited by 9 publications

(2 citation statements)

References 41 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The NW14A beamline is dedicated to the time resolved X-ray sciences. Besides pump-probe XAFS measurements [19][20][21][22]32,33], X-ray liquid scattering [34,35], X-ray diffraction [36], and X-ray single crystallography [37] techniques have been developed and have contributed to significant scientific achievements. There are two femtosecond lasers available to excite samples for pump-probe XAFS measurements.…”

Section: Methodsmentioning

confidence: 99%

Tracking the Local Structure Change during the Photoabsorption Processes of Photocatalysts by the Ultrafast Pump-Probe XAFS Method

et al. 2020

View full text Add to dashboard Cite

The birth of synchrotron radiation (SR) facilities and X-ray free electron lasers (XFELs) has led to the development of new characterization tools that use X-rays and opened frontiers in science and technology. Ultrafast X-ray absorption fine structure (XAFS) spectroscopy for photocatalysts is one such significant research technique. Although carrier behavior in photocatalysts has been discussed in terms of the band theory and their energy levels in reciprocal space (k-space) based on optical spectroscopic results, it has rarely been discussed where photocarriers are located in real-space (r-space) based on direct observation of the excited states. XAFS provides information on the local electronic and geometrical structures around an X-ray-absorbing atom and can address photocarrier dynamics in the r-space observed from the X-ray-absorbing atom. In this article, we discuss the time dependent structure change of tungsten trioxide (WO3) and bismuth vanadate (BiVO4) photocatalysts studied by the ultrafast pump-probe XAFS method in the femtosecond to nanosecond time scale with the Photon Factory Advanced Ring (PF-AR) and the SPring-8 Angstrom Compact free-electron LAser (SACLA). WO3 shows a femtosecond decay process of photoexcited electrons followed by a structural change to a metastable state with a hundred picosecond speed, which is relaxed to the ground-state structure with a nanosecond time constant. The Bi L3 edge of BiVO4 shows little contribution of the Bi 6s electron to the photoabsorption process; however, it is sensitive to the structural change induced by the photoexcited electron. Time-resolved XAFS measurements in a wide range time domain and with varied wavelengths of the excitation pump laser facilitate understanding of the overall details regarding the photocarrier dynamics that have a significant influence on the photocatalytic performance.

show abstract

Section: Methodsmentioning

confidence: 99%

Tracking the Local Structure Change during the Photoabsorption Processes of Photocatalysts by the Ultrafast Pump-Probe XAFS Method

et al. 2020

View full text Add to dashboard Cite

show abstract

“…The binding of O 2 to the tetramers is cooperative, and the most accepted explanations for binding and release behavior are the MWC (concerted) (5) and KNF (sequential) models (6). Much effort has been devoted to elucidating the mechanism of cooperativity, and some reviews and original articles are still periodically republished (7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19).…”

Section: Introductionmentioning

confidence: 99%

Roles of Fe-Histidine bonds in stability of hemoglobin: Recognition of protein flexibility by Q Sepharose

Nagatomo

Kitagawa

Nagai

2021

Biophysical Journal

View full text Add to dashboard Cite

Effects of allosteric effectors on oxygen binding to crystals of hemoglobin in the R‐quaternary structure

Shibayama

2024

Protein Science

View full text Add to dashboard Cite

Much is known about how allosteric effectors influence the equilibrium between the relaxed (R) and tense (T) states of hemoglobin (Hb), but little is known about how and to what extent the effectors lower the intrinsic O2 affinity of each allosteric state, especially the R‐state. Here, we provide a thorough characterization of the O2 equilibria of effector‐bound and unbound R‐quaternary form crystals of horse Hb without a quaternary structural switching. In the absence of effectors, R crystals of horse Hb were shown to bind O2 noncooperatively with a very high affinity virtually identical to that of R crystals of human Hb. We found that the effector bezafibrate (BZF) and its derivative L35 lower the overall O2 affinity of R crystals by approximately a factor of 3 and 2, respectively, while both maintaining noncooperative oxygenation. These effects are observed regardless of whether the effectors are co‐crystallized or soaked into the effector‐free protein crystals with a different lattice, confirming that the observed affinity reduction is induced by the BZF derivatives and not by crystal packing forces. Our findings, combined with available co‐crystal structural data, suggest that the BZF derivatives lower the O2 affinity of the R‐quaternary structure of Hb through structural constraints imposed by a quaternary shift slightly toward T. Additionally, since no co‐crystal of R‐state Hb with the effector inositol hexakisphosphate (IHP) is available, we only present an IHP‐soaking experiment showing little change in O2 affinity, and poor IHP binding to the R crystal structure of horse Hb is suggested.

show abstract

Size and Shape Controlled Crystallization of Hemoglobin for Advanced Crystallography

Cited by 9 publications

References 41 publications

Tracking the Local Structure Change during the Photoabsorption Processes of Photocatalysts by the Ultrafast Pump-Probe XAFS Method

Tracking the Local Structure Change during the Photoabsorption Processes of Photocatalysts by the Ultrafast Pump-Probe XAFS Method

Roles of Fe-Histidine bonds in stability of hemoglobin: Recognition of protein flexibility by Q Sepharose

Effects of allosteric effectors on oxygen binding to crystals of hemoglobin in the R‐quaternary structure

Contact Info

Product

Resources

About