Mean (SD) scores for the eight dimensions and the two summary measures of SF-36 for males and females aged 60–64 years.

<p>Mean (SD) scores for the eight dimensions and the two summary measures of SF-36 for males and females aged 60–64 years.</p

Factors across the life course and limited physical functioning (PF) from SF-36 (N = 1526).

<p>Model A: univariable regression analysis; Model B: includes childhood psychosocial factors and personality; Model C: includes all factors in Model B and adult social factors and health behaviours.</p

Factors across the life course and health related quality of life – physical component summary measure (PCS) (N = 1463).

<p>Model A: univariable regression analysis for those with complete covariate data; Model B multivariable regression: includes childhood psychosocial factors; and personality; Model C: includes all factors in Model B and adult social factors and health behaviours.</p

Childhood circumstances among members of the MRC National Survey of Health and Development who provided mental wellbeing data in 2006–11.

<p><b>Notes:</b> mean (sd) = mean (standard deviation)</p><p>Childhood circumstances among members of the MRC National Survey of Health and Development who provided mental wellbeing data in 2006–11.</p

Expression, Purification, and Properties of a Human Arachidonoyl-Specific Isoform of Diacylglycerol Kinase

Diacylglycerol kinase ε (DGKε) catalyzes the phosphorylation of diacylglycerol, producing phosphatidic acid. DGKε demonstrates exquisite specificity for the acyl chains of diacylglycerol. This contributes to the enrichment of particular acyl chains within the lipids of the phosphatidylinositol cycle. Phosphatidylinositol is highly enriched with 1-stearoyl-2-arachidonoyl, which is important for maintaining cellular health. Dysregulation of DGKε perturbs lipid signaling and biosynthesis, which has been linked to epilepsy, Huntington’s disease, and heart disease. Recessive loss-of-function mutations in the DGKε gene cause atypical hemolytic uremic syndrome. Because DGKε has never been purified, little is known about its molecular properties. We expressed human DGKε and a truncated version lacking the first 40 residues (DGKεΔ40) and purified both proteins to near homogeneity using nickel affinity chromatography. Kinase activity measurements showed that both purified constructs retained their acyl chain specificity for diacylglycerol with an activity level comparable to that of N-terminally FLAG epitope-tagged forms of these proteins expressed in COS7 cells. Both constructs lost activity upon being stored, particularly upon freezing and thawing, which was minimized by the addition of glycerol. Circular dichroism revealed that DGKε and DGKεΔ40 both contain significant amounts of α-helical and β structure and exhibit biphasic thermal denaturations. The loss of secondary structure upon heating was irreversible for both constructs, with relatively little effect of added dioleoylphosphatidylcholine. The addition of 50% glycerol stabilized both constructs and facilitated refolding of their secondary structures after heating. This is the first successful purification and characterization of DGKε’s enzymatic and conformational properties. The purification of DGKε permits detailed analyses of this unique enzyme and will improve our understanding of DGKε-related diseases