| nucleic acids, nucleotides, and nucleosides | Complex compounds of high molecular weight occurring in living cells. These are basically of two types, ribonucleic (RNA) and deoxyribonucleic (DNA) acids, both of which consist of nucleotides (nucleoside phosphates linked together by phosphate bridges). (12 Dec 1998) |
|---|---|
| nucleosides | Purine or pyrimidine bases attached to a ribose or deoxyribose. (12 Dec 1998) |
| purine | <biochemistry, molecular biology> A heterocyclic compound with a fused pyrimidine/imidazole ring. Planar and aromatic in character. The parent compound for the purine bases of nucleic acids. (18 Nov 1997) |
| purine 5'-nucleotidase | <enzyme> Associated with some immunologic deficiency diseases Registry number: EC 3.1.3.- (26 Jun 1999) |
| purine base | A purine. (05 Mar 2000) |
| purine-free diet | A diet containing a minimal quantity of purine bases (meats); liver, kidney, and sweetbread especially are excluded and replaced by dairy products, fruits, and cereals; alcoholic beverages also are excluded. Synonym: purine-free diet. (05 Mar 2000) |
| purine imidazole-ring cyclase | <enzyme> Recyclises ring-opened purine formamidopyrimidines in irradiated DNA, restoring the c-8 to n-9 band, does not require ATP Registry number: EC 6.3.3.- Synonym: purir cyclase (26 Jun 1999) |
| purine-nucleoside phosphorylase | <enzyme> An enzyme that catalyses the reaction between a purine nucleoside and orthophosphate to form a free purine plus ribose-5-phosphate. Chemical name: Purine-nucleoside:orthophosphate ribosyltransferase Registry number: EC 2.4.2.1 (12 Dec 1998) |
| purine permease | <chemical> Enzyme in transport system of purines in yeast pichia guillermondii Chemical name: permease, purine (26 Jun 1999) |
| purine phosphoribosyltransferase | <enzyme> Specific purine phosphoribosyltransferases are EC 2.4.2.7 and 2.4.2.8. Registry number: EC 2.4.2.- (26 Jun 1999) |
| purine-restricted diet | See: gout diet. (05 Mar 2000) |
| purine ribonucleoside | A toxic nucleoside isolated from the mushroom Agaricus nebularis and from Streptomyces sp. Synonym: 9-beta-ribofuranosylpurine, purine ribonucleoside, ribosylpurine. (05 Mar 2000) |
| low purine diet | A diet low in precursors of purines (such as tissues rich in cells with abundant nuclei, as in liver, glandular meats, etc.) to minimise formation of uric acid. Useful in treatment of patients with gout or urate-containing renal calculi. (05 Mar 2000) |