Purification and characterization of glucoamylase from Bacillus sp. isolated from root flora of Prunus mahaleb tree by LC-MS/MS analysis


Çelik M. S., KAPANCIK S., SEYRAN E., ÇETİNKAYA S.

International Journal of Biological Macromolecules, cilt.309, 2025 (SCI-Expanded, Scopus) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 309
  • Basım Tarihi: 2025
  • Doi Numarası: 10.1016/j.ijbiomac.2025.143078
  • Dergi Adı: International Journal of Biological Macromolecules
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, BIOSIS, Biotechnology Research Abstracts, CAB Abstracts, Chemical Abstracts Core, EMBASE, Food Science & Technology Abstracts, INSPEC, Veterinary Science Database
  • Anahtar Kelimeler: Bacillus sp., Characterization, Glucoamylase, Isolation, LC-MS/MS, Purification
  • Sivas Cumhuriyet Üniversitesi Adresli: Evet

Özet

Glucoamylases are enzymes that release free glucose by hydrolyzing consecutive α-1,4 bonds at the non-reducing ends of starch molecules. This enzyme was purified using ammonium sulfate precipitation, and its molecular mass was determined to be approximately 65.2 kDa via SDS-PAGE. Using zymogram analysis, the purified sample's active glucoamylase content was verified. Nano-Liquid Chromatography Mass Spectrometry (nLC-MS/MS) characterization identified peptides covering 46 % of the glucoamylase protein sequence, indicating partial characterization of the enzyme. It was found that the ideal pH and temperature for glucoamylase activity were 6.0 and 37 °C, respectively. Using soluble starch as a substrate, the kinetic parameters were calculated: the Km (substrate concentration at half-maximal velocity) was 30.21 μM, and the Vmax (maximum reaction velocity) was 35.59 μmol mg protein−1 min−1. The enzyme demonstrated optimal activity with soluble starch, highlighting its specificity for starch hydrolysis. Additionally, the enzymatic activity was enhanced in the presence of CaCl2, indicating a positive effect of calcium ions. Its optimal conditions and kinetic parameters provide valuable insights for its industrial and biomedical use.