No abstract

The APS Journal Legacy Content is the corpus of 100 years of historical scientific research from the American Physiological Society research journals. This package goes back to the first issue of each of the APS journals including the American Journal of Physiology, first published in 1898. The full text scanned images of the printed pages are easily searchable. Downloads quickly in PDF format.

No abstract

Human genetic variants predicted to cause loss-of-function of protein-coding genes (pLoF variants) provide natural in vivo models of human gene inactivation and can be valuable indicators of gene function and the potential toxicity of therapeutic inhibitors targeting these genes1,2. Gain-of-kinase-function variants in LRRK2 are known to significantly increase the risk of Parkinson’s disease3,4, suggesting that inhibition of LRRK2 kinase activity is a promising therapeutic strategy. While preclinical studies in model organisms have raised some on-target toxicity concerns5–8, the biological consequences of LRRK2 inhibition have not been well characterized in humans. Here, we systematically analyze pLoF variants in LRRK2 observed across 141,456 individuals sequenced in the Genome Aggregation Database (gnomAD)9, 49,960 exome-sequenced individuals from the UK Biobank and over 4 million participants in the 23andMe genotyped dataset. After stringent variant curation, we identify 1,455 individuals with high-confidence pLoF variants in LRRK2. Experimental validation of three variants, combined with previous work10, confirmed reduced protein levels in 82.5% of our cohort. We show that heterozygous pLoF variants in LRRK2 reduce LRRK2 protein levels but that these are not strongly associated with any specific phenotype or disease state. Our results demonstrate the value of large-scale genomic databases and phenotyping of human loss-of-function carriers for target validation in drug discovery.

Fibrinogen is the plasma protein which forms fibrin under the action of thrombin; hence, its properties are of importance in any consideration of blood coagulation. It was early identified in plasma by virtue of its insolubility in concentrated salt solutions3 and by its precipitation on moderate heating.4 In 1879 Hammarsten5 separated and purified this protein by a simple salting-out with half-saturated sodium chloride and this has been the classical method for its separa-tion6•7 although other salts such as ammonium sulfate8 and potassium phosphate9 have also been used. More recently fibrinogen has been shown also to comprise the largest component of the most insoluble major fraction separated from plasma by ethanol precipitation near pH 7 at low temperatures.10•u•12Although the initial separation of fibrinogen is readily accomplished, its further purification is made difficult on the one hand by the ever present danger of clotting13 and on the other hand by its high inherent lability. Procedures for its purification should, therefore, comprise as few steps and require as little time as possible and should avoid conditions which may promote clotting or denaturation.