Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00492 (hypoxanthine-guanine phosphoribosyltransferase)
 2,385 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Animal and in vitro studies have implicated decreased protein synthesis in the pathogenesis of tissue damage in phenylketonuria (PKU) and of growth failure in Lesch-Nyhan syndrome. Protein turnover was measured in vivo in ten young adult subjects with classical PKU, two subjects with hyperphenylalaninemia, and three children with Lesch-Nyhan syndrome using techniques based on continuous infusions of [13C]leucine and, in Lesch-Nyhan subjects, [2H5]phenylalanine. The PKU subjects had various degrees of dietary phenylalanine restriction and plasma phenylalanine levels at the time of study ranged from 450-1540 mumol/L (mean 1106). Plasma phenylalanine in the two hyperphenylalaninemic subjects was 533 and 402 mumol/L. Rates of protein synthesis in all PKU subjects (mean 3.71 g/kg/24 h, range 2.68-5.10, [13C]leucine as tracer) were in a range similar to or above control values (mean 2.97, range 2.78-3.22, n = 6), as were rates of protein catabolism (PKU mean 4.23 g/kg/24 h, range 3.15-5.45; controls 3.64, 3.50-3.91). Protein turnover values in hyperphenylalaninemia were also similar to those in controls. With [13C]leucine as tracer, both mean protein synthesis and catabolism values in Lesch-Nyhan subjects (mean 4.80 and 5.64 g/kg/24 h, respectively) were higher than values in control children matched for protein intake (synthesis 4.32 +/- 0.74 (SD) and catabolism 4.85 +/- 0.57 (g/kg/24 h, n = 5). Similar results were obtained in Lesch-Nyhan subjects using [2H5]phenylalanine as tracer. These results suggest that protein turnover is not decreased in either PKU or Lesch-Nyhan syndrome. This conclusion is inconsistent with the hypothesis that tissue damage in PKU results from impaired protein synthesis.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Protein metabolism in phenylketonuria and Lesch-Nyhan syndrome. 223 21