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C5H12O2N2 An amino acid occurring in the urine of some birds, but not found in native proteins.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.



H2N(CH2)3CH(NH2)COOH (also α, δ-di-aminovaleric acid), an amino acid that is readily soluble in water and alcohol.

Ornithine has one asymmetric carbon atom and exists in two optically active forms (D- and L-) and one racemic form, L-ornithine, found in the tissues of animals and humans, plays an important role in the biosynthesis of urea by the ornithine cycle. It is formed from arginine and α-amino-y-formylbutyric acid and may be converted to proline. Free L-ornithine is found in plants; bound L-ornithine is a component of several peptide antibiotics (bacitracin and gramicidin). L-ornithine has not been isolated from natural proteins.

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The contents of this supplement can therefore account for all of this patient's abnormal findings on metabolic testing, the excess arginine being converted to ornithine by arginase and [beta]-hydroxy-[beta]-methylbutyrate being synonymous with 3-hydroxyisovalerate (3-OH-IVA).
Successful early management of a female patient with a metabolic stroke due to ornithine transcarbamylase deficiency.
The age-related median values of seven amino acids (glycine, ornithine, alanine, leucine/isoleucine, tyrosine, aspartic acid, and glutamic acid) drop sharply from the zero-time point collected shortly after birth to the median of the 6-12 month age group (Figure 1).
Histidine, ornithine, and phenylalanine were three strongly and independently significant amino acids for the integrated metabolic panel and were finally adopted to develop the HOP panel based on the logistic regression model.
Abbreviations AMS: Altered mental status ICU: Intensive care unit OTC: Ornithine transcarbamylase TPN: Total parenteral nutrition.
The OTC is a mitochondrial enzyme that catalyzes the reaction between carbamoyl phosphate and ornithine to form citrulline, an essential step for the formation of nontoxic urea from ammonium [8].
marcescens produce magenta red pigment (prodigiosin) but former two species are negative for lysine and ornithine decarboxylase.
On the other hand, one possible mechanism would be to depend upon elevated concentration of ornithine, a precursor of polyamines, and might result from an increase in extra- hepatic arginase.
For in silico simulation of growth on arginine or succinate or ornithine as the sole source of carbon and nitrogen, we set the flux rate of glucose and ammonium to zero and flux rate of desired metabolite's uptake/exchange reaction to 10 mmol x g [DW.sup.-1] x [hr.sup.-1].
This, however, appeared to be the case for arginase (i.e., enrichment of ornithine derived from arginine) in solid tissues of living mice in the infusion model.
Putrescine is naturally produced in mammals by an enzyme called ornithine decarboxylase,or ODC, and is easily absorbed and cleared by the body.
Urea Cycle Disorders (UCD) are an important group of inborn errors of metabolism resulting from deficiencies of six different enzymes inherited as autosomal recessive, with the exception of Ornithine Transcarbamylase (OTC), which has X-linked inheritance.