ABSTRACT
The word “peptide” (πϵπτός) originally comes from Greek and means “small digestible.” Structurally, peptides are constituted by amino acids linked by amide bonds. It is commonly assumed that peptides contain up to 100 amino acids. Peptides play important physiological and biochemical functions in the human body, being involved in numerous biochemical processes within the nervous, immunological, and cardiovascular systems or intestine (Sewald and Jakubke 2009). Among them, peptides working as neurotransmitters, neuromodulators, or hormones (receptormediated signal transduction) are the best known.
