Lysine

An essential amino acid for collagen crosslinking and carnitine synthesis.

What lysine does in the body

Lysine is essential; the body cannot make it from any other substance. In collagen, lysine residues are converted to hydroxylysine by lysyl hydroxylase with vitamin C and iron; the copper-containing lysyl oxidase then links them together. This cross-linking gives skin, tendons, bones and vessel walls their tensile strength, and gives elastin its stretchiness. For carnitine, lysine residues in proteins receive methyl groups from SAM and are converted in several steps with vitamin C, iron and vitamin B6 into carnitine – the carrier that brings fatty acids into the mitochondria. On the histones, around which genetic material is wound, attachments on lysine residues switch genes on and off. Lysine is broken down in the liver to acetyl-CoA.

Low lysine – what happens in the body?

When little lysine is available, collagen is less cross-linked, and connective tissue, skin and bone are built less stably during renewal and repair. Less carnitine is produced, so fatty acids reach the mitochondria more slowly, and protein production as a whole is throttled. Lysine and arginine share transporters in the gut, kidney and cell membrane; for herpes viruses, which need arginine to multiply, this ratio is therefore being investigated in studies. Low values occur with low protein intake and with a diet consisting mainly of cereals, because cereals contain little lysine; strong heating additionally binds lysine in foods.

High lysine – what happens in the body?

Because lysine and arginine use the same transporters, a lot of lysine can reduce the absorption of arginine in the gut and its recovery in the kidney. Raised values arise after protein-rich meals, when breakdown in the liver is slower, and in the rare inherited condition hyperlysinaemia, which usually causes no complaints.

The interpretation is given in your report.