formyl peptidemedical dictionary

<biochemistry> Informal term for small peptides with a formylated N terminal methionine and usually a hydrophobic amino acid at the carboxy terminal end (fMetLeuPhe is the most commonly used).

These peptides stimulate the motor and secretory activities of leucocytes, particularly neutrophils and monocytes, that have a specific receptor (about 60 kD) of high affinity (Kd approximately 10exp 8M).

Leucocytes show chemotaxis towards formyl peptides but the term chemotactic peptides understates the range of activities the molecules will trigger. Thought to be synthetic analogues of bacterial signal sequences though this is unproven. The leucocytes of many animals (e.g. Pig, cow, chicken) do not respond.

This entry appears with permission from the Dictionary of Cell and Molecular Biology

(11 Mar 2008)