Air Pollution

Conversion of pepsinogen into pepsin is not a one-step process

“…Proteolytic activity measurements were made against haemoglobin at pH2 (Anson, 1948) and Azocoll at pH5.3 (Kay, 1975). Activation experiments with pepstatin were performed by adding pepstatin (6.2mg/ml in methanol; 0.14ml) to 32ml of 3.2mM-HCl and mixing with a Vibramixer.…”

The Development of a New Thermophoretic Precipitator for Scanning Transmission Electron Microscope Analysis of Ultrafine Aerosol Particles

“…A number of different thermal precipitators have been developed over the years (e.g., Kay 1952, 1957, Mercer 1973, many of which have been based on the original design of Green and tson. Notable exprecipitators deand Orr (1964) which sampled aerosol, of these allowed continuous sampling onto a moving substrate.…”

The influence of molecular size and pH on the macrocationic inhibition of pepsin by polylysine

“…Kumar & Kassell 1977) and polylysine (Anderson 1970) inhibition of pepsin have usually been based on the use of milk-clotting systems for enzyme activity determination but these systems are understandably complex, and end point determination involves a subjective observation; furthermore, variability of the dried milk substrate depending on its source and manner of drying make comparison of results difficult (unpublished observations from this laboratory). Many of the problems of the milk clotting tests were avoided in the present work by using the chromogenic substrate azocoll, used by Kay (1975) for pepsin, which has been found suitable for studying polylysine inhibition, the only difficulty being the laborious necessity t o weigh out the insoluble substrate into every flask. The linear relationships which necessarily underly quantitative interpretations of the enzyme activity and inhibition results were easily shown.…”