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A method for covalently attaching heparin to agarose in which the bound heparin is resistant to detachment is described. A controlled amount of 4-aminophenethylamine is linked to trichloro-s-triazine-activated agarose via the primary amino group. The resulting immobilized arylamine is then diazo coupled to an appropriately modified heparin. The immobilized heparin was used in a two-step procedure for the purification of mouse antithrombin. Some of the properties of the mouse antithrombin are described. 相似文献
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Scots pine ( Pinus sylvestris L.) is generally resistant to chilling temperatures. Porphyrin metabolism under low temperature stress was studied in etiolated seedlings of Scots pine. Low temperatures affect porphyrin accumulation in at least 3 different temperature sensitive sites: 1) the light activated accumulation of 5-aminolevulinic acid, a porphyrin precursor, 2) the metabolism of 5-aminolevulinic acid to form porphyrins and 3) a preferential accumulation of chlorophyll a over chlorophyll b . The temperature sensitivity of pine is compared to maize ( Zea mays L.), a chilling sensitive plant. 相似文献
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Three regions of esterase activity designated I, II, and III were found on zymograms of vitreous fluids. Region I, the most anodal, exhibited two zones, one of which (the slower) was in all samples, occasionally accompanied by a second band which moved just ahead of it. Likewise, Region III, the most cathodal, exhibited two phenotypes, a common one-band and a rare two-band phenotype. Region II was occupied by one- and two-banded combinations of five different zones (a, b, c, d and e), which indicated that each band was the product of an allelic series of genes (EsII a , EsII b , etc.).
Only 11 of 15 expected phenotypes were encountered because of the rarity of alleles EsIIa and EsII c . The most common allele, EsII b , had a frequency of 0.83 in Puget Sound hake and 0.60 in Pacific Ocean hake; this difference was highly significant. In the Pacific Ocean population agreement was good between observed and expected numbers, assuming Hardy-Weinberg equilibrium. In the Puget Sound samples deviations from expected frequencies did not appear in females or first-year fish, but deviations were significant in males 2 years and older; these deviations occurred as a marked deficiency of bd males combined with an excess of bb and dd males, particularly the latter. Inhibition tests indicated that these isozymes are B esterases. Estimations of molecular weight for the isozymes of Region II based on chromatographic and ultracentrifugation methods were 70,000 and 73,500, respectively. 相似文献
Only 11 of 15 expected phenotypes were encountered because of the rarity of alleles EsII
159.
The addition of 10% fetal bovine serum to Leibovitz's L-15 culture medium resulted in marked growth of peripheral blood leukocytes from rainbow trout, Salmo gairdneri. Culture medium without serum or with 20% homologous serum did not induce substantial growth. In contrast to what has been reported by others, oxygenation of the culture medium was found not to be required for excellent cell growth. 相似文献