Analysis of protonation equilibria of some alanyl dipeptides in water and aqueous ethanol mixtures

Karaca T. D., Doğan A.

Amino Acids, cilt.55, 2023 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 55
  • Basım Tarihi: 2023
  • Doi Numarası: 10.1007/s00726-023-03238-9
  • Dergi Adı: Amino Acids
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, BIOSIS, CAB Abstracts, Chemical Abstracts Core, Communication Abstracts, EMBASE, MEDLINE, Metadex, Veterinary Science Database, Civil Engineering Abstracts
  • Anahtar Kelimeler: Alanyl dipeptides, Protonation constants, Ethanol-water
  • Gazi Üniversitesi Adresli: Evet

Özet

© 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.The protonation constants are one of the most fundamental properties of biological molecules. The determination of the constants of the dipeptide is interesting and necessary for a full understanding of its activities in biological process. In this study, the protonation constants of some aliphatic alanine dipeptides (alanyl-alanine, alanyl-phenylalanine, alanyl-valine, alanyl-leucine, and alanyl-methionine) were studied in water and ethanol–water mixtures (20%ethanol–80%water;40%ethanol–60%water;60%ethanol–40%water, (v/v)) at 25 ± 0.1 °C under nitrogen atmosphere and ionic strength at 0.10 mol L−1 by potentiometry. The constants of the systems were calculated using Best computer program. The effects of the different amino acids bound to the alanine on the acidity of the alanyl dipeptides were investigated. The constants were influenced by changes in solvent composition and their variations were discussed in terms of solvent and structural properties.