scholarly journals Elucidation of the mechanism of subunit exchange in αB crystallin oligomers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Rintaro Inoue ◽  
Yusuke Sakamaki ◽  
Takumi Takata ◽  
Kathleen Wood ◽  
Ken Morishima ◽  
...  
Keyword(s):  
Small Angle Neutron Scattering ◽  
Protein Concentration ◽  
Eye Lens ◽  
Analytical Ultracentrifuge ◽  
Small Molecular Weight ◽  
Subunit Exchange ◽  
Dilute Sample ◽  
Αb Crystallin ◽  
Contrast Matching

AbstractAlphaB crystallin (αB-crystallin) is a key protein for maintaining the long-term transparency of the eye lens. In the eye lens, αB-crystallin is a “dynamical” oligomer regulated by subunit exchange between the oligomers. To elucidate the unsettled mechanism of subunit exchange in αB-crystallin oligomers, the study was carried out at two different protein concentrations, 28.5 mg/mL (dense sample) and 0.45 mg/mL (dilute sample), through inverse contrast matching small-angle neutron scattering. Interestingly, the exchange rate of the dense sample was the same as that of the dilute sample. From analytical ultracentrifuge measurements, the coexistence of small molecular weight components and oligomers was detected, regardless of the protein concentration. The model proposed that subunit exchange could proceed through the assistance of monomers and other small oligomers; the key mechanism is attaching/detaching monomers and other small oligomers to/from oligomers. Moreover, this model successfully reproduced the experimental results for both dense and dilute solutions. It is concluded that the monomer and other small oligomers attaching/detaching mainly regulates the subunit exchange in αB-crystallin oligomer.

scholarly journals Satellite-Derived Protein Concentration of Phytoplankton in the Southwestern East/Japan Sea

2021 ◽  
Vol 9 (2) ◽  
pp. 189
Author(s):  
Hyeonji Bae ◽  
Dabin Lee ◽  
Jae Joong Kang ◽  
Jae Hyung Lee ◽  
Naeun Jo ◽  
...  
Keyword(s):  
Protein Concentration ◽  
Japan Sea ◽  
Biological Properties ◽  
Measured Data ◽  
Trophic Levels ◽  
Coefficient Of Determination ◽  
P Value ◽  
Chl A ◽  
Major Factors

The cellular macromolecular contents and energy value of phytoplankton as primary food source determine the growth of higher trophic levels, affecting the balance and sustainability of oceanic food webs. Especially, proteins are more directly linked with basic functions of phytoplankton biosynthesis and cell division and transferred through the food chains. In recent years, the East/Japan Sea (EJS) has been changed dramatically in environmental conditions, such as physical and chemical characteristics, as well as biological properties. Therefore, developing an algorithm to estimate the protein concentration of phytoplankton and monitor their spatiotemporal variations on a broad scale would be invaluable. To derive the protein concentration of phytoplankton in EJS, the new regional algorithm was developed by using multiple linear regression analyses based on field-measured data which were obtained from 2012 to 2018 in the southwestern EJS. The major factors for the protein concentration were identified as chlorophyll-a (Chl-a) and sea surface nitrate (SSN) in the southwestern EJS. The coefficient of determination (r2) between field-measured and algorithm-derived protein concentrations was 0.55, which is rather low but reliable. The satellite-derived estimation generally follows the 1:1 line with the field-measured data, with Pearson’s correlation coefficient, which was 0.40 (p-value < 0.01, n = 135). No remarkable trend in the long-term annual protein concentration of phytoplankton was found in the study area during our observation period. However, some seasonal difference was observed in winter protein concentration between the 2003–2005 and 2017–2019 periods. The algorithm is developed for the regional East/Japan Sea (EJS) and could contribute to long-term monitoring for climate-associated ecosystem changes. For a better understanding of spatiotemporal variation in the protein concentration of phytoplankton in the EJS, this algorithm should be further improved with continuous field surveys.

scholarly journals Mutations in Human αA-Crystallin/sHSP Affect Subunit Exchange Interaction with αB-Crystallin

PLoS ONE ◽  
2012 ◽  
Vol 7 (2) ◽  
pp. e31421 ◽  
Author(s):  
Ilangovan Raju ◽  
Lalita Oonthonpan ◽  
Edathara C. Abraham
Keyword(s):  
Exchange Interaction ◽  
Subunit Exchange ◽  
Αb Crystallin

scholarly journals Kinetic Asymmetry of Subunit Exchange of Homooligomeric Protein as Revealed by Deuteration-Assisted Small-Angle Neutron Scattering

2011 ◽  
Vol 101 (8) ◽  
pp. 2037-2042 ◽  
Author(s):  
Masaaki Sugiyama ◽  
Eiji Kurimoto ◽  
Hirokazu Yagi ◽  
Kazuhiro Mori ◽  
Toshiharu Fukunaga ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Subunit Exchange

scholarly journals Mutant alleles differentially shape cattle complex traits and fitness

2021 ◽  
Author(s):  
Ruidong Xiang ◽  
Ed Breen ◽  
Sunduimijid Bolormaa ◽  
Christy Vander Jagt ◽  
Amanda Chamberlain ◽  
...  
Keyword(s):  
Somatic Cell ◽  
Cell Count ◽  
Complex Traits ◽  
Somatic Cell Count ◽  
Protein Concentration ◽  
Opposite Effect ◽  
Gestation Length ◽  
Hybrid Vigour ◽  
Term Selection

Classical mutations tend to be deleterious to traits and fitness. Is this the case for mutations with polygenic effects? Here, we infer ancestral and mutant alleles (MAs) for 8 million sequence variants in 113k cattle and quantify the effects of MA on 37 complex traits. Heterozygosity at sites conserved across 100 vertebrates increase fertility, stature, and milk production, positively associating these traits with fitness. MAs decrease fat and protein concentration in milk and stature but increase gestation length and somatic cell count in milk indicative of mastitis. However, the frequency of MAs that decrease fat and protein concentration and stature and increase gestation length and somatic cell count is lower than the frequency of MAs with the opposite effect. These results suggest bias in the direction of effect of mutation (e.g. towards reduced protein in milk), but selection operating to reduce the frequency of these MAs. MAs with a large-effect decrease protein and milk yield, while small-effect MAs increase the two traits. These results imply two classes of genomic sites subject to long-term selection: sites conserved across vertebrates show hybrid vigour while sites subject to less long-term selection show a bias in mutation towards alleles that are selected against.

Porosity of the Marcellus Shale: A contrast matching small-angle neutron scattering study

2018 ◽  
Vol 188 ◽  
pp. 156-164 ◽  
Author(s):  
Jitendra Bahadur ◽  
Leslie F. Ruppert ◽  
Vitaliy Pipich ◽  
Richard Sakurovs ◽  
Yuri B. Melnichenko
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Marcellus Shale ◽  
Scattering Study ◽  
Neutron Scattering Study ◽  
Contrast Matching

Adaptation of the hepatic transudation barrier to sinusoidal hypertension

2020 ◽  
Vol 318 (4) ◽  
pp. R722-R729 ◽  
Author(s):  
Ranjeet M. Dongaonkar ◽  
Christopher M. Quick ◽  
Glen A. Laine ◽  
Karen Uray ◽  
Charles S. Cox ◽  
...  
Keyword(s):  
Reflection Coefficient ◽  
Protein Concentration ◽  
Interstitial Fluid ◽  
Fluid Pressure ◽  
Vena Cava ◽  
Barrier Properties ◽  
Venous Hypertension ◽  
Lymph Flow ◽  
Acute Changes

The role of the hepatic transudation barrier in determining ascites volume and protein content in chronic liver disease is poorly understood. Therefore, the purpose of the present study was to characterize how chronic sinusoidal hypertension impacts hepatic transudation barrier properties and the transudation rate. The suprahepatic inferior vena cava was surgically constricted, and animals were exposed to either short-term (SVH; 2–3 wk) or long-term venous hypertension (LVH; 5–6 wk). Compared with SVH, LVH resulted in lower peritoneal fluid pressure, ascites volume, and ascites protein concentration. The transudation barrier protein reflection coefficient was significantly higher, and the transudation barrier hydraulic conductivity, transudation rate, and transudate-to-lymph protein concentration ratio were significantly lower in LVH animals compared with SVH animals. The sensitivity of transudation rates to acute changes in interstitial fluid pressures was also significantly lower in LVH animals compared with SVH animals. In contrast, there was no detectable difference in hepatic lymph flow rate or sensitivity of lymph flow to acute changes in interstitial fluid pressures between SVH and LVH animals. Taken together, these data suggest that decreased hepatic transudation barrier permeability to fluid and protein and increased reflection coefficient led to a decrease in the hepatic contribution to ascites volume. The present work, to the best of our knowledge, is the first to quantify an anti-ascites adaptation of the hepatic transudation barrier in response to chronic hepatic sinusoidal hypertension.

scholarly journals Small Angle Neutron Scattering from Nanophase Titanium As A Function of Oxidation

1988 ◽  
Vol 132 ◽  
Author(s):  
J. A. Eastman ◽  
J. E. Epperson ◽  
H. Hahn ◽  
T. E. Klippert ◽  
A. Narayanasamy ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Scattering Length ◽  
Contrast Variation ◽  
Gas Condensation ◽  
Pressure Oxygen ◽  
Scattering Centers ◽  
Scattering Lengths ◽  
Contrast Matching

ABSTRACTNanophase titanium, prepared by the gas-condensation method both as aggregated powder and in lightly compacted discs, has been studied by conventional small angle neutron scattering, and by use of contrast variation methods. The contrast has been changed (a), isotopically, by means of deuterated/protonated solvents distilled into the specimen and (b) by progressive incremental oxidation of the Ti particles using fixed doses of low-pressure oxygen. It was shown that some evolution of the small angle pattern for lightly compacted nanophase Ti occurred over a period of several months at 300 K. Contrast matching by external solvent works well and has allowed the scattering lengths of oxidized and unoxidized specimens to be followed. The results imply that the scattering from metal and oxide can be separated under suitable conditions. The partial oxidation experiments indicate that there is both a fast and slow oxidation at 300 K. Also, during slow oxidation, high scattering length density scattering centers were formed whose number increased, but whose size remained the same at about 2 nm; these centers are tentatively assumed to be TiO2.

Sign in / Sign up

Export Citation Format

Share Document