🧬 A pigment enzyme 🍏 A browning enzyme

tyrosinase

1 9.8

A substance in plants, fungi, and bacteria that makes cut fruit and vegetables turn brown

noun
/taɪˈrɒsɪneɪs/

Specialized

: tirosinasa

Primer sequences were devised from the published sequence for human tyrosinase cDNA (n7) (fig 1).
tyrosinase mRNA
tyrosinase gene
Detection of tyrosinase

Examples

No tyrosinase mRNA was detected in the cell line M5, one of the two amelanotic lines tested.

Academic text (1992)
The difference in detection levels between cell lines could reflect different extents of transcription of the tyrosinase gene.

Academic text (1992)
Photo (black & white): Fig 3 -- Detection of tyrosinase mRNA in blood of cancer patients.

Academic text (1992)
PCR was used to amplify the gene for tyrosinase, a tissue-specific gene in melanocytes.

Academic text (1992)
The tyrosinase gene contains several introns, so for DNA amplification by PCR, we selected primers represented on different exons of the gene.

Academic text (1992)
Since normal melanocytes are not thought to circulate in peripheral blood, detection of tyrosinase transcription in peripheral blood should indicate the presence of circulating cancer cells.

Academic text (1992)
DETECTION OF TYROSINASE AND Beta GLOBIN mRNA IN CANCER PATIENTS AND HEALTHY SUBJECTS PREFORMATTED TABLE

Academic text (1992)
Tyrosinase mRNA was detected in blood samples from four of the seven patients with malignant melanoma, but in none of the healthy controls or patients with other cancers (see table, fig 3).

Academic text (1992)
With outer primers alone and 30 cycles of PCR, tyrosinase mRNA from the equivalent of 50 cells or more was easily detected in the melanoma cell lines SK-mel-19, SK-mel-23, and SK-mel-28.

Academic text (1992)
The enzyme tyrosinase is responsible for the browning that occurs in cut apples as it oxidizes the exposed phenolic compounds.

Surface Forms

tyrosinase singular

tyrosinases plural

Morphology

tyrosinase = tyrosine (semi-transparent) = tyrosine + ase

Formed from the amino acid name 'tyrosine' plus the enzyme-forming suffix '-ase', which signals an enzyme acting on or related to tyrosine; clear to those with biochemical knowledge but not to average B1 learners.

Etymology

The word tyrosinase comes from tyrosine, whose name comes from the Greek tyros meaning 'cheese' because it was first found in cheese, plus the enzyme ending -ase. So tyrosinase means 'the enzyme that works on tyrosine', which is why it causes fruits and vegetables to turn brown when they are cut.