Studies on porphobilinogen

作者：Phyllis E. Brockman, C. H. Gray · 发表于：Biochemical Journal · 年份：1953 · DOI：10.1042/bj0540022 · 被引用次数：22 · 研究领域：Porphyrin Metabolism and Disorders

The term porphobilinogen will be used in the present paper for the colourless chromogen excreted in acute porphyria, often in association with free porphyrins, their metal complexes and other pigments, and responsible for the reaction with p-dimethylaminobenzaldehyde (Ehrlich's aldehyde reagent) giving a chloroform-insoluble red pigment.The chromogen itself has not yet been isolated, but crude solutions have been prepared by chromatography and shown to form in acid solution a mixture of porphyrins and porphobilin, a highly polar bile pigment with properties resembling urobilin (Waldenstrom & Vahlquist, 1939a; Prunty, 1945).Waldenstrom & Vahlquist, on the basis of molecular weight deter- minations by the diffusion method, proposed that porphobilinogen was a dipyrryl compound, two molecules of which could condense together to give a bile pigment or, in accordance with the theory of Dobriner, Strain & Localio (1937), a porphyrin.Neuberger, Muir & Gray (1950) have emphasized that such a mechanism was unlikely to give rise to naturally occurring porphyrins which are of types I and III only.Recently, Hawkinson & Watson (1952) and also Herbert (1952) have observed that ethyl acetate extracts of porphyria urines contained a colourless porphyrin precursor not reacting with p-dimethylaminobenzaldehyde but forming a porphyrin on irradiation with ultraviolet light or on oxidation.The work of Herbert may be interpreted as sug- gesting that the increased amounts of porphyrin obtained on he...