The levels of some pteridines increased significantly if there is a tumour inside the body.
He said that the oncopterin level in urine indicates whether cancer is likely to develop, and varying levels of the six pteridines can actually provide a "fingerprint" of the type of cancer.
These experiments foreshadow the long range goals of an effort to understand the structure, function and regulation of a specific pteridine biosynthetic gene during the development of a multicellular eukaryotic organism.
A genetic analysis of the pteridine biosynthetic enzyme, guanosine triphosphate cyclohydrolase, in Drosophila melanogaster.
The chemistry of the pteridines
has developed during a period of over a century and to undertake a general review of the area is no mean task.
Neopterin, an aromatic pteridine
derived from intracellular guanosine triphosphate, is released primarily by human macrophages and monocytes on stimulation by T-lymphocyte-derived interferon-[gamma] (IFN-[gamma]).
derivatives (6,7-dimethyltetrahydropterin and sepiapterin) were from Schircks Laboratories.
Folate is a general term related to a family of substances containing a pteridine
ring joined to both p-aminobenzoic acid and glutamic acid (1,5).
The rate of elongation of the glutamate chain length of folates is a function of both the pteridine
ring structure of the folate and the number of glutamate residues.
The phenylalanine concentrations, urinary pteridine
values, and PTPS enzyme activities in red blood cells (16) are summarized in Table 1.
Folyl-polyglutamates do not bind to oxy-Hb tetramers, although removal of the pteridine
moiety produces binding of the resulting p-aminobenzoylpolyglutamate residues (26).
Neopterin originates from GTP, which is transformed by a specific enzyme, GTP-cyclohydrolase 1, into the first detectable intermediate of pteridine
biosynthesis, 7,8-dihydroneopterin triphosphate.