scholarly journals Mass spectrometry analysis of human P2X1 receptors; insight into phosphorylation, modelling and conformational changes

2012 ◽  
Vol 123 (5) ◽  
pp. 725-735 ◽  
Author(s):  
Jonathan A. Roberts ◽  
Andrew R. Bottrill ◽  
Sharad Mistry ◽  
Richard J. Evans
2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniel L. Hurdiss ◽  
Ieva Drulyte ◽  
Yifei Lang ◽  
Tatiana M. Shamorkina ◽  
Matti F. Pronker ◽  
...  

Abstract The human betacoronaviruses HKU1 and OC43 (subgenus Embecovirus) arose from separate zoonotic introductions, OC43 relatively recently and HKU1 apparently much longer ago. Embecovirus particles contain two surface projections called spike (S) and haemagglutinin-esterase (HE), with S mediating receptor binding and membrane fusion, and HE acting as a receptor-destroying enzyme. Together, they promote dynamic virion attachment to glycan-based receptors, specifically 9-O-acetylated sialic acid. Here we present the cryo-EM structure of the ~80 kDa, heavily glycosylated HKU1 HE at 3.4 Å resolution. Comparison with existing HE structures reveals a drastically truncated lectin domain, incompatible with sialic acid binding, but with the structure and function of the esterase domain left intact. Cryo-EM and mass spectrometry analysis reveals a putative glycan shield on the now redundant lectin domain. The findings further our insight into the evolution and host adaptation of human embecoviruses, and demonstrate the utility of cryo-EM for studying small, heavily glycosylated proteins.


1987 ◽  
Vol 253 (5) ◽  
pp. E496-E502 ◽  
Author(s):  
P. F. Bougneres ◽  
P. Ferre

Ketone body kinetics were quantified in six children (3-5 yr old), who were fasted for 13-22 h, by a combined perfusion of [3-13C]acetoacetate ([13C]AcAc) and D-(-)-beta-[4,4,4-2H3]hydroxybutyrate (beta-[2H3]OHB) and gas chromatography-mass spectrometry analysis. Results were analyzed according to the "single-pool" (combined enrichments) or the "two-accessible pools" models. After 20-22 h of fasting, ketone body turnover rate was 30-50 mumol.kg-1.min-1, a rate achieved after several days of fasting in adults. At low ketosis, acetoacetate was the ketone body preferentially synthesized de novo and utilized irreversibly. When ketosis increased, acetoacetate irreversible disposal was not enhanced, since it was largely converted into beta-OHB, whereas beta-OHB irreversible disposal was very much increased. The single-pool and two-pool models gave similar ketone body turnover rates when [13C]AcAc was the tracer, whereas the use of beta-[2H3]OHB gave some more divergent results, especially at low ketosis. These studies demonstrate that ketogenesis is very active in short-term fasted children and that the use of a combined infusion of [13C]AcAc and beta-[2H3]OHB is a convenient way to give insight into individual ketone body kinetics.


Sign in / Sign up

Export Citation Format

Share Document