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Protoporphyrinogen oxidase and porphobilinogen deaminase in variegate porphyria
Author(s) -
MEISSNER P. N.,
DAY R. S.,
MOORE M. R.,
DISLER P. B.,
HARLEY E.
Publication year - 1986
Publication title -
european journal of clinical investigation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.164
H-Index - 107
eISSN - 1365-2362
pISSN - 0014-2972
DOI - 10.1111/j.1365-2362.1986.tb01339.x
Subject(s) - protoporphyrinogen oxidase , porphobilinogen deaminase , porphyria , porphobilinogen , medicine , chemistry , acute intermittent porphyria , endocrinology , protoporphyrin , enzyme , biochemistry , biology , porphyrin
. Two enzymes of the haem biosynthetic pathway were investigated in patients with variegate porphyria. Protoporphyrinogen oxidase in cultures of Epstein‐Barr virus transformed lymphoblasts from twenty‐seven patients showed a mean maximal velocity ( V max ) of 0·39 ± 0·08 + nmol of protoporphyrin mg protein ‐1 h ‐1 , a 52% reduction ( P < 0·001) from a non‐porphyric control group (0·82 ± 0·10). K m values (1·00 ± 0·27 μ M) did not differ significantly ( P > 0·05) from control values in any of the patients. The mean V max of porphobilinogen deaminase in the cultures was 1·50 ± 0·18 nmol of uroporphyrin mg protein ‐1 min ‐1 , a 24% reduction ( P < 0·001) from controls (1·94 ± 0·14). Mean porphobilinogen deaminase activity in the erythrocytes of twenty‐one patients with variegate porphyria was 8·37 ± 1·99 nmol of uroporphyrin 1 erythrocytes ‐1 s ‐1 , a 28% reduction ( P < 0·001) from normal (11·98 ± 2·11). The reduced activities of these two enzymes comply with the expression of variegate porphyria during its quiescent and acute phases.