Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:4.2.1.22 (cystathionine beta-synthase)
 965 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three circumstances prompted us to reexamine the relationship between abnormal cystathionine accumulation and possible homocystinuria resulting from this condition: (a) discovery of an infant girl with apparently alternating massive cystathioninuria and homocystinuria; (b) the presence of homocystinuria in some, but not all, previously reported cases of cystathioninuria probably due to gamma-cystathionine deficiency; and (c) the recent demonstration that mammalian cystathionine beta-synthase can cleave cystathionine to homocysteine. The following conclusions were reached: (a) Homocystine may arise as a result of bacterial contamination of a urine sample initially containing cystathionine, but not homocystine. (b) After a methionine load, a cystathioninuric patient may excrete readily detected amounts of homocystine. (c) However, homocystinuria is not a necessary concomitant of even massive cystathioninuria. These findings and some of their implications are briefly discussed.
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PMID:Cystathioninuria and homocystinuria. 112 32

Twenty-nine amino acids were analyzed in the sera of 105 adult Senegambian goitrous patients classified as stages I, II, and III according to World Health Organization recommendations. Mean serum concentration of all essential amino acids revealed highly significant drops (p less than 0.001) as goiter stage increased, except for methionine (Met). Most nonessential amino acids (NEAA) and intermediary metabolites were similarly characterized by a general decrease to the subnormal range, although some resisted depression in stages II and III. Homocystine (Hcy) demonstrated a unique pattern in that it was the only NEAA distinguished by regularly rising serum levels. These data are consistent with the view that endemic goiter is associated with overall stepwise downregulation in protein metabolism. In addition to iodine restriction, generalized malnutrition may aggravate the goitrogenic processes. Serum levels of Met and Hcy strongly suggest that the first step of the transsulfuration pathway is impaired in protein-depleted states due to cystathionine beta-synthase (EC 4.2.1.22) deficiency.
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PMID:Nutritional significance of alterations in serum amino acid patterns in goitrous patients. 308 Aug 69