I've taken an introductory course that included a little bit of crystallography, but it stopped after basic Bravais lattice descriptions. I know how to label planes and directions and calculate the packing factor with a plane, but I can't follow along with my boss when he discusses diffraction patterns at work. I eventually want to learn how to index diffraction peaks and perform basic analysis on powders with XRD, but have no idea where to start.
Sorry if this doesn't belong here since it's not a direct science question.
Hi there!!!
I just wanted to sahre with you a video I made speaking about crystallographic groups and with some examples from the Alhambra palace!
https://www.youtube.com/watch?v=VpuFVdmvHws&t=4s
Hope you like it.
Can someone explain it to me or guide me to some articles that talk precisely about this ? thank you so much !
A crystalline metal–peptide pore entraps chiral alcohols and ketones in a single‐crystal‐to‐single‐crystal manner. Crystallographic analyses revealed their chemical structures, chiral conformations, and even an unstable equilibrium product.
Abstract
Porous metal complexes enable single‐crystal X‐ray crystallographic observation of included guests or reaction intermediates through simple soaking with the guests/substrates. Previous studies on this technique have often encountered difficulties in the observation of chiral structures because the host frameworks had no chirality. We synthesized a new metal–peptide porous complex through a folding‐and‐assembly strategy and utilized the chiral pore for trapping chiral guests. Chiral alcohols and ketones were successfully included within the pore. Crystallographic analyses clearly revealed not only their chemical structures but also chiral transformation events within the pore such as fixed conformations or an unstable hemiacetal formation.
https://ift.tt/307q2rr
NifB is an essential radical SAM enzyme for the assembly of an 8Fe core of the nitrogenase cofactor. Here we report the crystal structures of Methanobacterium thermoautotrophicum NifB without (apo Mt NifB) and with (holo Mt NifB) a full complement of three [Fe4S4] clusters. Both apo and holo Mt NifB contain a partial TIM barrel core; yet, unlike apo Mt NifB that is structurally disordered outside the TIM barrel, holo Mt NifB is fully assembled and competent in cofactor biosynthesis. Of the three [Fe4S4] clusters in holo Mt NifB, the canonical radical SAM (RS)‐cluster, like those in other radical SAM enzymes, is coordinated by three Cys ligands; whereas the adjacently positioned K1‐ and K2‐clusters, representing the precursor to an 8Fe cofactor core, are each coordinated by one His and two Cys ligands. Prediction of substrate channels, combined with in silico docking of SAM in holo Mt NifB, suggests plausible binding of SAM between the RS‐ and K2‐clusters and putative paths for entry of SAM and exit of products of SAM cleavage, thereby providing important mechanistic insights into the radical SAM‐dependent carbide insertion concomitant with cofactor core formation.
https://ift.tt/36QshTL
Journal of the American Chemical SocietyDOI: 10.1021/jacs.0c10337
Hua Lu, Takayuki Nakamuro, Keitaro Yamashita, Haruaki Yanagisawa, Osamu Nureki, Masahide Kikkawa, Han Gao, Jiangwei Tian, Rui Shang, and Eiichi Nakamura
https://ift.tt/37wf6rj
Title says it all! I'm studying for crystallography, but I don't have hundreds of convenient wooden shapes at home to work with (and even then, I'd like to be able to check whether my conclusions about each shape are correct).
Does anyone know of a piece of software or some interactive website for this purpose? Currently have Krystalshaper, and while it's sort of what I'm looking for, it doesn't tell me the symmetry elements of every crystal shape (only the crystallographic axes and rotation axes, though nothing in the way of mirror planes or roto-inversion axes).
Suggestions are much appreciated!
Journal of the American Chemical SocietyDOI: 10.1021/jacs.0c06143
https://ift.tt/2EUtiyA
So I know there are plenty of studies about the crystallographic structure of lots of proteins and porins but what exactly do they contribute for? What information can it give us? On what can it help us for further studies?
Journal of the American Chemical SocietyDOI: 10.1021/jacs.0c10779
William J. Howitz, Micha Wierzbicki, Rudy William Cabanela, Cindy Saliba, Ariana Motavalli, Ngoctran Tran, and James S. Nowick
https://ift.tt/3dOocku
Mopping up with MOFs: Efficient removal of toxic oxoanions of 79SeVI and AsV is highly desirable for the remediation of hazardous waste, which poses a severe environmental threat. The capture of toxic oxanions of SeVI and AsV through the use of iMOF‐1C as a rapid, high capacity, and selective sorbent is demonstrated and rare crystallographic evidence for the ion‐exchange process is presented.
Abstract
Selectively capturing toxic oxoanions of selenium and arsenic is highly desired for the remediation of hazardous waste. Ionic metal–organic frameworks (iMOFs) especially cationic MOFs (iMOF‐C) as ion‐exchange materials, featuring aqueous phase stability, present a robust pathway for sequestration of the oxoanions owing to their ability to prevent leaching because of their ionic nature. On account of scarcity of water‐stable cationic MOFs, the capture of oxoanions of selenium and arsenic has been a major challenge and has not been investigated using iMOFs. Herein, we demonstrate large scale synthesis of cationic MOF, viz. iMOF‐1C that exhibits selective capture of oxoanions of SeVI (SeO42−) and AsV (HAsO42−) in water with a maximum sorption capacity of 100 and 85 mg g−1, respectively. This represents among the highest uptake capacities observed for selenate oxoanion in MOFs. Further, the ion‐exchange mechanism was directly unveiled by single crystal analysis, which revealed variable modes of host–guest binding.
https://ift.tt/2SX5Fsi
Chiral optical metamaterials with delicate structures are in high demand in various fields due to their strong light–matter interactions. Recently, a scalable strategy for the synthesis of chiral plasmonic nanoparticles using amino acids and peptides has been reported. In this work, three‐dimensional chiral gold nanoparticles using dipeptide γ‐Glu‐Cys and Cys‐Gly were synthesized and analyzed from a crystallographic perspective. The γ‐Glu‐Cys‐directed nanoparticles showed a cube‐like outline with a protruded chiral wing. Meanwhile, the nanoparticles synthesized with Cys‐Gly exhibited a rhombic dodecahedron‐like outline with curved edges and elliptical cavities on each face. Intermediate morphology analysis indicated that γ‐Glu‐Cys generated an intermediate morphology of concave hexoctahedron, while Cys‐Gly formed a concave rhombic dodecahedron. Nanoparticles synthesized with Cys‐Gly were named 432 helicoid V due to their unique morphology and growth pathway.
https://ift.tt/3aCSQu1
NifB is an essential radical SAM enzyme required for the assembly of an 8Fe core of the nitrogenase cofactor. Here we report the crystal structures of Methanobacterium thermoautotrophicum NifB without and with a full complement of three [Fe4S4] clusters, which provide important mechanistic insights into the radical SAM‐dependent carbide insertion concomitant with the formation of a cofactor core.
Abstract
NifB is an essential radical SAM enzyme required for the assembly of an 8Fe core of the nitrogenase cofactor. Herein, we report the X‐ray crystal structures of Methanobacterium thermoautotrophicum NifB without (apo MtNifB) and with (holo MtNifB) a full complement of three [Fe4S4] clusters. Both apo and holo MtNifB contain a partial TIM barrel core, but unlike apo MtNifB, holo MtNifB is fully assembled and competent in cofactor biosynthesis. The radical SAM (RS)‐cluster is coordinated by three Cys, and the adjacent K1‐ and K2‐clusters, representing the precursor to an 8Fe cofactor core, are each coordinated by one His and two Cys. Prediction of substrate channels, combined with in silico docking of SAM in holo MtNifB, suggests the binding of SAM between the RS‐ and K2‐clusters and putative paths for entry of SAM and exit of products of SAM cleavage, thereby providing important mechanistic insights into the radical SAM‐dependent carbide insertion concomitant with cofactor core formation.
https://ift.tt/2JGjREO
NifB is an essential radical SAM enzyme required for the assembly of an 8Fe core of the nitrogenase cofactor. Here we report the crystal structures of Methanobacterium thermoautotrophicum NifB without and with a full complement of three [Fe4S4] clusters, which provide important mechanistic insights into the radical SAM‐dependent carbide insertion concomitant with the formation of a cofactor core.
Abstract
NifB is an essential radical SAM enzyme required for the assembly of an 8Fe core of the nitrogenase cofactor. Herein, we report the X‐ray crystal structures of Methanobacterium thermoautotrophicum NifB without (apo MtNifB) and with (holo MtNifB) a full complement of three [Fe4S4] clusters. Both apo and holo MtNifB contain a partial TIM barrel core, but unlike apo MtNifB, holo MtNifB is fully assembled and competent in cofactor biosynthesis. The radical SAM (RS)‐cluster is coordinated by three Cys, and the adjacent K1‐ and K2‐clusters, representing the precursor to an 8Fe cofactor core, are each coordinated by one His and two Cys. Prediction of substrate channels, combined with in silico docking of SAM in holo MtNifB, suggests the binding of SAM between the RS‐ and K2‐clusters and putative paths for entry of SAM and exit of products of SAM cleavage, thereby providing important mechanistic insights into the radical SAM‐dependent carbide insertion concomitant with cofactor core formation.
https://ift.tt/36QshTL
Selectively capturing toxic oxoanions of selenium (Se) and arsenic (As) is highly desired for the remediation of hazardous waste. Ionic metal‐organic frameworks (iMOFs) especially cationic MOFs (iMOF‐C) as ion‐exchange materials, featuring aqueous phase stability, present a robust pathway for sequesteration of aforementioned anions due to no leaching associated with its inherent ionic nature. Owing to the scarcity of water stable cationic MOFs, capture of oxoanions of selenium and arsenic has been a major challenge and has not been investigated using iMOFs. Herein, we demonstrate large scale synthesis of cationic MOF towards selective capture of oxoanions of Se(VI) (SeO 4 2 ‐ ) and As(V) (HAsO 4 2 ‐ ) in water with a maximum sorption capacity of 100 and 85 mg/g respectively. This represents among the highest uptake capacity observed for selenate oxoanion in MOFs. Further, the ion‐exchange mechanism was directly unveiled by single crystal analysis which revealed variable mode of host‐guest binding.
https://ift.tt/2SX5Fsi
Mopping up with MOFs: Efficient removal of toxic oxoanions of 79SeVI and AsV is highly desirable for the remediation of hazardous waste, which poses a severe environmental threat. The capture of toxic oxanions of SeVI and AsV through the use of iMOF‐1C as a rapid, high capacity, and selective sorbent is demonstrated and rare crystallographic evidence for the ion‐exchange process is presented.
Abstract
Selectively capturing toxic oxoanions of selenium and arsenic is highly desired for the remediation of hazardous waste. Ionic metal–organic frameworks (iMOFs) especially cationic MOFs (iMOF‐C) as ion‐exchange materials, featuring aqueous phase stability, present a robust pathway for sequestration of the oxoanions owing to their ability to prevent leaching because of their ionic nature. On account of scarcity of water‐stable cationic MOFs, the capture of oxoanions of selenium and arsenic has been a major challenge and has not been investigated using iMOFs. Herein, we demonstrate large scale synthesis of cationic MOF, viz. iMOF‐1C that exhibits selective capture of oxoanions of SeVI (SeO42−) and AsV (HAsO42−) in water with a maximum sorption capacity of 100 and 85 mg g−1, respectively. This represents among the highest uptake capacities observed for selenate oxoanion in MOFs. Further, the ion‐exchange mechanism was directly unveiled by single crystal analysis, which revealed variable modes of host–guest binding.
https://ift.tt/2SX5Fsi
