Get Phases from Arsenic Anomalous Scattering: de novo SAD Phasing of Two Protein Structures Crystallized in Cacodylate Buffer

The crystal structures of two proteins, a putative pyrazinamidase/nicotinamidase from the dental pathogen Streptococcus mutans (SmPncA) and the human caspase-6 (Casp6), were solved by de novo arsenic single-wavelength anomalous diffraction (As-SAD) phasing method. Arsenic (As), an uncommonly used element in SAD phasing, was covalently introduced into proteins by cacodylic acid, the buffering agent in the crystallization reservoirs. In SmPncA, the only cysteine was bound to dimethylarsinoyl, which is a pentavalent arsenic group (As (V)). This arsenic atom and a protein-bound zinc atom both generated anomalous signals. The predominant contribution, however, was from the As anomalous signals, which were sufficient to phase the SmPncA structure alone. In Casp6, four cysteines were found to bind cacodyl, a trivalent arsenic group (As (III)), in the presence of the reducing agent, dithiothreitol (DTT), and arsenic atoms were the only anomalous scatterers for SAD phasing. Analyses and discussion of these two As-SAD phasing examples and comparison of As with other traditional heavy atoms that generate anomalous signals, together with a few arsenic-based de novo phasing cases reported previously strongly suggest that As is an ideal anomalous scatterer for SAD phasing in protein crystallography

Oxidative Neurodegeneration Is Prevented by UCP0045037, an Allosteric Modulator for the Reduced Form of DJ-1, a Wild-Type of Familial Parkinson’s Disease-Linked PARK7

Although a loss-of-function mutation has been identified in familial Parkinson’s disease PARK7, the wild-type of DJ-1 is known to act as an oxidative stress sensor in neuronal cells. Recently, we identified UCP0045037 as a compound that bound to the reduced form of DJ-1 by in silico virtual screening. In this study, we determined the neuroprotective effects of UCP0045037 against focal cerebral ischemia-induced neurodegeneration in rats. Hydrogen peroxide-induced cell death was significantly inhibited by UCP0045037 in both rat mesencephalic dopaminergic neurons and human normal SH-SY5Y cells. In contrast, DJ-1-knockdown SH-SY5Y cells lost the protective activity of UCP0045037. These results suggest that UCP0045037 interacts with endogenous DJ-1 and produces a neuroprotective response

BAG1 restores formation of functional DJ-1 L166P dimers and DJ-1 chaperone activity

The L166P mutation in DJ-1 is associated with Parkinson’s disease. DJ-1–interacting protein BAG1 chaperones mutant DJ-1 and reverses its mutant phenotype

A prospective, randomised comparison of single and three piece acrylic foldable intraocular lenses

Aims: To compare the postoperative performance of single and three piece acrylic foldable intraocular lenses (IOLs). Methods: 20 patients underwent bilateral cataract surgery with a single piece SA30AL IOL in one eye and a three piece MA30BA IOL in the other eye. The eyes were randomly assigned to either a single or three piece lens. The amount of IOL decentration and tilt, area of anterior capsule opening, and degree of posterior capsule opacification were measured using the Scheimpflug anterior segment analysis system (Nidek EAS-1000). Visual acuity and contrast sensitivity were examined. Measurements were performed by masked examiners before and 1 day, 1 week, 1, 3, 6, and 18 months after surgery. Results: There were no significant differences between the two groups (p>0.05, paired t test) in the amount of IOL decentration, IOL tilt, area of anterior capsule opening, degree of posterior capsule opacification, best corrected visual acuity, and contrast sensitivity throughout the 18 month follow up period. Conclusion: The single and three piece acrylic foldable IOLs are equally stable in the eye after surgery

Crystallization and preliminary crystallographic analysis of p40phox, a regulatory subunit of NADPH oxidase

Human p40phox was expressed, purified and crystallized. Diffraction data were collected to a resolution of 3.0 Å

Thiobacillus ferrooxidansによるジャロサイトおよびアンモニオジャロサイトの生成実験

金沢大学理工研究域地球社会基盤学系Jarosite KFe3(SO4)2(OH)6 and ammoniojarosite NH4Fe3(SO4)2(OH)6 were experimentaly formed in 9 K-medium with Thiobacillus ferrooxidans at 33℃ under acidic condition. The product shows characteristic peaks of jarosite at 3.08, 1.99 and 1.83 A , and those of ammoniojarosite at 3.09, 5.12, 1.98 and 1.83 A in use X-ray powder diffraction and electron diffraction pattern. TEM and SEM observations revealed the crystal growth processes of these minerals as follows ; Bacillus bacterial cells take the form of cross-finger. Both iron and sulfur components precipitated on cell wall. The iron component takes the form of burs, whereas the sulfur component forms rosary-shaped materials. The sizes of iron materials range from 0.5 to 2.0 μm in diameter while those of sulfur materials range from 0.05 to 0.1μm in diameter. Next, potassium and hydroxyl in 9 K-medium reacted on both iron and sulfur components on the cell wall. Cubic or platy jarosite, 0.1 to 5.0μm in diameter, is formed within 3 days. Jarosite of final products changed to reform rosary or parallel crystalline materials. Potassium in jarosite is substituted for ammonia to form ammoniojarosite within 5 days. Jarosite was produced by bacterial mineralization in 9 K-medium within 3 days, and those of ammoniojarosite within 5 days. Without Thiobacillus ferrooxidans, jarosite and ammoniojarosite were produced after 5 or 9 days respectively. The results suggest that Thiobacillus ferrooxidans contributes formation of jarosite and ammoniojarosite as catalyst.Jarosite KFe3(SO4)2(OH)6 and ammoniojarosite NH4Fe3(SO4)2(OH)6 were experimentaly formed in 9 K-medium with Thiobacillus ferrooxidans at 33℃ under acidic condition. The product shows characteristic peaks of jarosite at 3.08, 1.99 and 1.83 A , and those of ammoniojarosite at 3.09, 5.12, 1.98 and 1.83 A in use X-ray powder diffraction and electron diffraction pattern. TEM and SEM observations revealed the crystal growth processes of these minerals as follows ; Bacillus bacterial cells take the form of cross-finger. Both iron and sulfur components precipitated on cell wall. The iron component takes the form of burs, whereas the sulfur component forms rosary-shaped materials. The sizes of iron materials range from 0.5 to 2.0 μm in diameter while those of sulfur materials range from 0.05 to 0.1μm in diameter. Next, potassium and hydroxyl in 9 K-medium reacted on both iron and sulfur components on the cell wall. Cubic or platy jarosite, 0.1 to 5.0μm in diameter, is formed within 3 days. Jarosite of final products changed to reform rosary or parallel crystalline materials. Potassium in jarosite is substituted for ammonia to form ammoniojarosite within 5 days. Jarosite was produced by bacterial mineralization in 9 K-medium within 3 days, and those of ammoniojarosite within 5 days. Without Thiobacillus ferrooxidans, jarosite and ammoniojarosite were produced after 5 or 9 days respectively. The results suggest that Thiobacillus ferrooxidans contributes formation of jarosite and ammoniojarosite as catalyst