The good taste of peptides

Abstract

The taste of peptides is seldom one of the most relevant issues when one considers the many important biological functions of this class of molecules. However, peptides generally do have a taste, covering essentially the entire range of established taste modalities: sweet, bitter, umami, sour and salty. The last two modalities cannot be attributed to peptides as such because they are due to the presence of charged terminals and/or charged side chains, thus reflecting only the zwitterionic nature of these compounds and/or the nature of some side chains but not the electronic and/or conformational features of a specific peptide. The other three tastes, that is, sweet, umami and bitter, are represented by different families of peptides. This review describes the main peptides with a sweet, umami or bitter taste and their relationship with food acceptance or rejection. Particular emphasis will be given to the sweet taste modality, owing to the practical and scientific relevance of aspartame, the well-known sweetener, and to the theoretical importance of sweet proteins, the most potent peptide sweet molecules.

Examination of the Potential for Adaptive Chirality of the Nitrogen Chiral Center in Aza-Aspartame

“…On tasting, the authors concluded that aza-aspartame 9 was slightly bitter or tasteless. Notably, the threshold for bitter compounds generally appears to be lower than that of sweet compounds [7]. The absence of a sweet taste may be due to the flat sp 2 hybridization of the nitrogen in the urea moiety of 9 as well as inability for the sp 3 nitrogen to exhibit dynamic chirality preventing recognition by the receptors for sweetness.…”

“…For example, in functional assays on HEK-293 cells stably expressing different mouse melanocortin receptor (MCR) subtypes (mMC1R, mMC3R, mMC4R, and mMC5R) replacement of aza-arginine for arginine in the melanocyte-stimulating hormone (MSH) tetra-peptide 5 gave [aza-Arg 3 ]MSH 6, which exhibited a drop of activity at the mMC1R that was less significant than that of the [D-Arg 3 ]MSH isomer; however, more significant losses of activity than both isomers on the other receptor subtypes ( Figure 2) [6]. In the interest of further exploring the adaptive chirality of nitrogen in an aza-peptide analog, we selected to make an aza-analog of the sugar substitute aspartame, because earlier studies had demonstrated that the S,S-and R,S-diastereomers (Figure 4) exhibited sweet and bitter tastes, respectively [7]. Aza-aspartame 9 became an interesting target by which to judge the existence of adaptive chirality in an azapeptide, because of the potential for a bitter sweet taste by adaptation to the chirality of each diastereomer of the peptide counterpart at the different receptors on the tongue.…”

Fraksinasi Dan Karakterisasi Komponen Rasa Gurih Pada Bumbu Penyedap

“…Rasa gurih merupakan salah satu dari lima rasa dasar yaitu manis, pahit, asam dan asin (Temussi, 2011). Diketahui beberapa senyawa memiliki kontribusi terhadap timbulnya rasa umami, yaitu monosodium glutamat (MSG), inosin monofosfat (IMP) dan guanosin monofosfat (GMP) (Kuninaka, 1967).…”

“…Hasil beberapa penelitian menunjukkan bahwa peptida yang diperoleh dari hasil hidrolisis protein, baik protein nabati (SchlichtherleCerny dan Amadò, 2002) atau hewani (Maehashi et al, 1999) yang mempunyai rasa gurih. Peptida yang mempunyai rasa gurih mengandung asam glutamat dalam sekuennya yaitu H-Lys-Gly-Asp-Glu-Glu-SerLeu-Ala-OH (Temussi, 2011).…”

Biologically Active Peptides Released From Food Proteins

“…delicious peptide) wyizolowany z bulionu wołowego i zbudowany z ośmiu reszt aminokwasowych KGDEESLA. Wrażenie smakowe umami przypisywane jest też krót-szym fragmentom tej sekwencji, takim jak: GD, DE, EE, KG oraz sekwencjom: GDG, AEA, VEV, DL, EEE [100]. Analiza właściwości sensorycznych peptydów nie jest prosta.…”