Measurement of heme synthesis levels in mammalian cells

Abstract

Heme serves as the prosthetic group for a wide variety of proteins known as hemoproteins, such as hemoglobin, myoglobin and cytochromes.It is involved in various molecular and cellular processes such as gene transcription, translation, cell differentiation and cell proliferation. Thebiosynthesis levels of heme vary across different tissues and cell types and is altered in diseased conditions such as anemia, neuropathyand cancer. This technique uses [4-14C] 5-aminolevulinic acid ([14C] 5-ALA), one of the early precursors in the heme biosynthesis pathway tomeasure the levels of heme synthesis in mammalian cells. This assay involves incubation of cells with [14C] 5-ALA followed by extraction ofheme and measurement of the radioactivity incorporated into heme. This procedure is accurate and quick. This method measures the relativelevels of heme biosynthesis rather than the total heme content. To demonstrate the use of this technique the levels of heme biosynthesis weremeasured in several mammalian cell lines.