Structural and functional characterization of cold-active sialidase isolated from Antarctic fungus Penicillium griseofulvum P29

• Published in: Biochemistry and Biophysics Reports
• Main Authors: Aleksandar Dolashki, Radoslav Abrashev, Dimitar Kaynarov, Ekaterina Krumova, Lyudmila Velkova, Rumyana Eneva, Stefan Engibarov, Yana Gocheva, Jeny Miteva-Staleva, Vladislava Dishliyska, Boryana Spasova, Maria Angelova, Pavlina Dolashka
• Format: Article in Journal/Newspaper
• Language: English
• Published: Elsevier 1481
• Subjects: Antarctic fungi; Sialidase; Cold-active enzyme; Structural characterization; 3D-structure; Fluorescence analysis; Biology (General); QH301-705.5; Biochemistry; QD415-436; Antarctic; Terra Nova Bay; Antarc*; Antarctica
• Online Access: https://doi.org/10.1016/j.bbrep.2023.101610; https://doaj.org/article/897e11fc99ad4f11b32bcd2d14843cb0

The fungal strain, Penicillium griseofulvum P29, isolated from a soil sample taken from Terra Nova Bay, Antarctica, was found to be a good producer of sialidase (P29). The present study was focused on the purification and structural characterization of the enzyme. P29 enzyme was purified using a Q-Sepharose column and fast performance liquid chromatography separation on a Mono Q column. The determined molecular mass of the purified enzyme of 40 kDa by SDS-PAGE and 39924.40 Da by matrix desorption/ionization mass spectrometry (MALDI-TOF/MS) analysis correlated well with the calculated mass (39903.75 kDa) from the amino acid sequence of the enzyme. P29 sialidase shows a temperature optimum of 37 °C and low-temperature stability, confirming its cold-active nature. The enzyme is more active towards α(2 → 3) sialyl linkages than those containing α(2 → 6) linkages.Based on the determined amino acid sequence and 3D structural modeling, a 3D model of P29 sialidase was presented, and the properties of the enzyme were explained. The conformational stability of the enzyme was followed by fluorescence spectroscopy, and the new enzyme was found to be conformationally stable in the neutral pH range of pH 6 to pH 9. In addition, the enzyme was more stable in an alkaline environment than in an acidic environment. The purified cold-active enzyme is the only sialidase produced and characterized from Antarctic fungi to date.