An early intermediate in the biosynthesis of biotin: Incorporation studies with [1,7-14C2]pimelic acid

Abstract

1. An unknown biotin vitamer was obtained in high yields in culture filtrates of Penicillium chrysogenum. 2. Production of this vitamer and desthiobiotin is controlled by the biotin concentration in the medium. 3. The unknown vitamer becomes labelled when the organism is grown in the presence of radioactive pimelic acid. 4. Chromatographic procedures were developed for the purification of the radioactive vitamer. 5. The vitamer is extremely stable in concentrated acid but gives rise to new vitamers under certain conditions. 6. The intermediate role of this vitamer in the synthesis of biotin is discussed.

Biosynthesis of Biotin by Microörganisms

“…A compound of the same Rf value as the unknown vitamer was reported by GENGHOF (3) in Corynebacterium xerosis, by DHYSE and HERTZ (4) in Escherichia coli, and by EISENBERG and MASEDA (5) in Penicillium chrysogenum.…”

The Biotin‐Dependent Enzymes

“…A pathway based on these investigations and consistent with nutritional ) genetic (204)(205)(206)(207)(208)(209)(210)(211), and labeling studies (203,(212)(213)(214)(215)(216)(217)(218) is illustrated in Figure 5.…”

“…5 ) was proposed initially on the basis of nutritional (183)(184)(185)(186)(187)(188)191,193,(195)(196)(197)(198)(199)(200)202) and labeling studies (203,(212)(213)(214)216). An unidentified amino acid vitamer of biotin, labeled during growth on 1,7-14C-pimelate (203) and incorporated into biotin (217), was thought to be the condensation product of pimelate and serine or alanine (215).…”

“…5 ) was proposed initially on the basis of nutritional (183)(184)(185)(186)(187)(188)191,193,(195)(196)(197)(198)(199)(200)202) and labeling studies (203,(212)(213)(214)216). An unidentified amino acid vitamer of biotin, labeled during growth on 1,7-14C-pimelate (203) and incorporated into biotin (217), was thought to be the condensation product of pimelate and serine or alanine (215). Alternatively it has been proposed (188,216) that cysteine was the 3-C condensing partner, although sulfur incorporation concomitant with a 3-C unit has not been demonstrated and a consistent stimulation of biotin biosynthesis by cysteine has not been obtained (187,188,191,196,202 5) has been demonstrated in whole cell preparations (194,201).…”

Biotin: Biogenesis, Transport, and Their Regulation

“…The evidence was based on the electrophoretic mobility of the vitamer, its avidinuncombinability, and the absence of sulfur in the molecule (42). Independently, both Eisenberg (43,44) and Iwahara et al (45) showed that the vitamer was labeled with 1,7-14C-pimelic acid and that the isolated labeled compound could be incorporated either into biotin or dethiobiotin. Both groups identified the compound as 7-keto-8-aminopelargonic acid and suggested an intermediary role for this vitamer in biotin biosynthesis (46)(47)(48).…”