Characteristics and applications of a novel thermostable phospholipase for modification and processing of phospholipids (Lecithin)

2022 Fiscal Year Final Research Report

• Project/Area Number: 19K05898
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 38050:Food sciences-related
• Research Institution: Kyoto Prefectural University
• Principal Investigator: Tsujimoto Yoshiyuki 京都府立大学, 生命環境科学研究科, 講師 (20315930)
• Project Period (FY): 2019-04-01 – 2023-03-31
• Keywords: ホスホリパーゼ / リン脂質 / レシチン / リン脂質改変 / 脂肪酸メチルエステル

Outline of Final Research Achievements

The characteristics of phospholipase A (PlaA) from Caenibacillus caldisaponilyticus B157T strain were studied. It is suggested that PlaA is initially secreted as an inactive form with a C-terminal pro-sequence (PlaA-Cpro) and becomes active through extracellular processing. Recombinant PlaA-Cpro was expressed in Escherichia coli and processed in vitro to obtain active recombinant PlaA (rPlaA). rPlaA showed strong and stable enzymatic activity across various pH and temperature conditions. It preferred the sn-1 position of phospholipids but had little hydrolytic activity on neutral lipids. Furthermore, rPlaA could recognize the assembly state of substrates and surfactants. It was also found that rPlaA facilitated the synthesis of fatty acid methyl esters from phospholipids and methanol, as well as the exchange of fatty acids between phospholipids and neutral lipids.

Free Research Field

発酵生理学、応用微生物学、脂質生化学

Academic Significance and Societal Importance of the Research Achievements

好熱性細菌B157T株が生産するホスホリパーゼ（PlaA）が広範囲のpHや温度で安定であり、sn-1位に高い選択性を持つPLA1であったため、市販酵素の代替酵素として十分対応できる酵素であると考えられる。また、本酵素は、脂肪酸メチルエステルの合成やリン脂質の脂肪酸を中性脂質の脂肪酸に交換するのに利用できることを明らかにした。本酵素は、相同性の高いタンパク質が報告されていない新規酵素であるため、脂質関連酵素の基質認識の理解や脂質関連酵素の特性解明に大きな貢献が期待されるだけではなく、環境負荷の少ないリン脂質の改変や加工において産業利用の可能性を示している。