Showing papers in "Journal of Biological Chemistry in 1948"

TL;DR: In the present investigations of the chromatographic separation of amino acids, it has been observed that, when the color development is carried out in tubes exposed to the air, these difficulties appear to result primarily from the influence of dissolved oxygen.

TL;DR: The quantitative determination of the pyridine nucleotides and of substrates which can be brought into stoichiometric reaction with them has been hampered by the lack of reliable extinction coefficients for these substances.

TL;DR: It was possible to show that a rearrangement of the red pigment does occur during the enzymic oxidation, that synthetic dihydroxyphenylalanine melanin is probably a polymer of indoled, 6-quinone, and that the inferred o-quinonoid formulation of thered pigment is correct.

TL;DR: The discovery of carbon dioxide assimilation by heterotrophic bacteria and animal tissues aroused considerable interest in the mechanisms involved and Evans, Vennesland, and Slotin discovered that pigeon liver extracts fixed in the presence of malate, pyruvate, and catalytic amounts of manganous ions and of either diphosphopyridine nucleotide (DPN) or triphosphoyridineucleotide (TPN), while catalyzing the overall Reaction 1.

TL;DR: Previous conditions in which phenolphthalein glucuronide was employed as substrate (1) have proved unsatisfactory for the determination of glucuronidase in plasma, serum, and laked blood cells, but these problems have now been largely overcome by the introduction of a deproteinizing procedure and by otherwise modifying the conditions of assay.

TL;DR: The medium herein proposed has been extensively investigated with respect to its suitability for Lactobacillus arabinosus 17-5, Streptococcus faecalis R, and Leuconostoc mesenteroides P-60 and supports acid production equal to or greater than had been previously reported with specialized media for each organism.

TL;DR: The reaction catalyzed by this enzyme consists in the oxidation of a -CHO to a -COO group and represents the first oxidative step in the degradation of carbohydrate in the tissues.

TL;DR: The publications on Kjeldahl’s method for determining nitrogen may outnumber those on any other analytical method in the same period of time and the immense usefulness of the method is attributable to its immense usefulness.

TL;DR: The results of assays for coenzyme A in various materials show a ubiquitous distribution of coen enzyme A in living cells.

TL;DR: In the course of an investigation of the inhibition of crystalline pancreatic proteolytic enzymes by specific low molecular weight compounds the discovery was made that crystalline trypsin is likewise a powerful catalyst for the hydrolysis of certain amino acid esters.

TL;DR: It will be shown that similar cross-linking can also occur between aminomethylol groups and phenol, imidazole, or indole groups and the reactions involving amino groups, formaldehyde, and the reaction mixture.

TL;DR: The methods described here for the demonstration of choline and of reducing sugars will possibly be applicable to the quantitative microestimation of these substances.

TL;DR: Methods for determinations of vitamin C dehydro-Z-ascorbic (DHA), DHA, and DKA in the presence of each other are reported, indicating that these derivatives are identical substances.

TL;DR: Thiourea was chosen for study because of its solubility in water, ease of purification, and availability, and the development of a new colorimetric reaction with a higher extinction coefficient was of critical importance in studies.