| hybrid enzyme | <biochemistry> An enzyme in a heterozygous individual which has subunits with slightly different sequences of amino acids than other copies of the same enzyme. This occurs because the two alleles of the genes which code for each subunit are slightly different (due to the heterozygosity), so that either of the two versions of the subunit could be produced for any copy of the enzyme. (09 Oct 1997) |
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| hydrolytic enzyme | <biochemistry> See hydrolase. (18 Nov 1997) |
| new yellow enzyme | The d-amino-acid oxidase found in yeast, a flavoenzyme, which contains FAD as coenzyme instead of FMN as does NADPH dehydrogenase; so-called to distinguish it from Warburg's old yellow enzyme. Compare: amino acid oxidases. (05 Mar 2000) |
| defect, enzyme | An abnormality in the protein (enzyme) important in catalyzing a normal biochemical reaction in the body. Disorders result from a deficiency (or functional abnormality) of an enzyme. Archibald Garrod in 1902 was the first to attribute a disease to an enzyme defect: an inborn error of metabolism. Today, newborns are routinely screened for certain enzyme defects such as phenylketonuria (PKU) and galactosaemia, an error in the handling (metabolism) of the sugar galactose. (12 Dec 1998) |
| D enzyme | Dextrin transglycosylase or glycosyltransferase;a 4-glycosyltransferase converting maltodextrins into amylose and glucose by transferring parts of 1,4-glucan chains to new 4-positions on glucose or other 1,4-glucans. Synonym: amylomaltase, D enzyme, dextrin glycosyltransferase, dextrin transglycosylase, disproportionating enzyme. (05 Mar 2000) |
| disproportionating enzyme | Dextrin transglycosylase or glycosyltransferase;a 4-glycosyltransferase converting maltodextrins into amylose and glucose by transferring parts of 1,4-glucan chains to new 4-positions on glucose or other 1,4-glucans. Synonym: amylomaltase, D enzyme, dextrin glycosyltransferase, dextrin transglycosylase, disproportionating enzyme. (05 Mar 2000) |
| immobilised enzyme | <biochemistry> An enzyme attached to a solid support over which substrate is passed and is converted into product. (09 Oct 1997) |
| Q enzyme | <enzyme> Converts amylose to amylopectin. (10 Oct 1997) |
| induced enzyme | Inducible enzyme, an enzyme that can be detected in a growing culture of a microorganism, after the addition of a particular substance (inducer) to the culture medium, but was not detectable prior to the addition and can act on the inducer. A prototype is the beta-galactosidase of Escherichia coli, synthesised upon the addition of various galactosides, whether or not these are good substrates. Compare: constitutive enzyme. Synonym: adaptive enzyme. (05 Mar 2000) |
| interleukin-1 converting enzyme | <biochemistry> Cytoplasmic cysteine protease that is uniquely responsible for cleaving proIL-1_ (31 or 33 kD) into mature IL-1_ (17.5 kD), the active cytokine is then released by a nonstandard mechanism (there is no signal sequence and it does not pass through the Golgi). The enzyme seems to be composed of two nonidentical subunits derived from a single proenzyme. The ICE gene has some homology with the ced 9 gene of C. Elegans, the product of which is involved in mediating cell death by apoptosis. (11 Mar 1998) |
| intracellular enzyme | <enzyme> An enzyme that performs its functions within the cell that produces it; most enzyme's are intracellular enzyme's. Synonym: endoenzyme. (05 Mar 2000) |
| old yellow enzyme | <enzyme> A flavoprotein that reversibly oxidises NADPH to NADP and a reduced acceptor. Chemical name: NADPH:(acceptor) oxidoreductase Registry number: EC 1.6.99.1 (12 Dec 1998) |
| T enzyme | 1,4-alpha-d-glucan 6-alpha-d-glucosyltransferase. (05 Mar 2000) |
| terminal addition enzyme | <enzyme> A non-template-directed DNA polymerase normally found in vertebrate thymus and bone marrow. It catalyses the elongation of oligo- or polydeoxynucleotide chains and is widely used as a tool in the differential diagnosis of acute leukaemias in man. Chemical name: Nucleoside-triphosphate:DNA deoxynucleotidylexotransferase Registry number: EC 2.7.7.31 (12 Dec 1998) |
| thermostable enzyme | <enzyme> An enzyme that is not readily subject to destruction or alteration by heat. Synonym: heat-stable enzyme. (05 Mar 2000) |