Isolation of a thermostable legume chitinase and study on the antifungal activity

Abstract

Chitinases are listed as one class of pathogenesis-related proteins, and they have become a popular research topic because of their resistance to plant-pathogenic diseases. A chitinase with antifungal activity was isolated from the Canadian cranberry beans (Phaseolus vulgaris). The procedure included extraction, ammonium sulfate precipitation, affinity chromatography on Affi-gel blue gel, CM-Sephadex C-50, and Sephadex G-75. There was an almost 108-fold increase in specific activity of the purified chitinase compared with that of the crude extract. The enzyme exhibited a molecular mass of 30.6 kDa in sodium dodecyl sulfate-polyacrylamide gel electrophoresis both under reducing and non-reducing conditions, indicating that it was a monomeric protein. The pI was determined to be 7.6 by isoelectric-focusing electrophoresis. The optimum pH and the optimum temperature for activity towards N-acetyl-glucosamine was 5.4 and 40-55 degrees C, respectively. It exerted a potent inhibitory action toward fungal species including Botrytis cinerea, Physalospora piricola, Fusarium oxysporum, and Pythium aphanidermatum. The chitinase was thermostable up to 58 degrees C in both enzymatic reaction and antifungal activity. The present findings demonstrated a thermostable chitinase from cranberry beans with potentially exploitable significance.

A novel thermostable chitinase (PJC) from pomegranate (Punica granatum) juice

“…DTT and b-mercaptoethanol, but slightly increased in the presence of anionic detergent SDS (106%). PJC activity was moderately inhibited by Hg 2+ but strongly inhibited by Mn 2+ , which contrasts with another plant chitinase from cranberry beans (Wang, Shao, Fu, & Rao, 2009).…”

A novel chitinase isolated from Vicia faba and its antifungal activity

“…During the previous decades, chitinases have received increased attention because of their wide range of applications. Practical applications of chitinases include use in the preparation of protoplasts from fungi, as a protective agent against plant-pathogenic fungi (Taira, Toma, & Ishihara, 2005;Wang, Shao, Fu, & Rao, 2009;Wang, Shao, Rao, Lee, & Ye, 2007;Ye & Ng, 2002.…”

Purification and Biochemical Characterization of a Pathogenesis Related Endochitinase Arachis hypogaea

“…Antifungal effect of chitinases have been extensively studied in many plants including mung bean (Ye and Ng, 2005), lima bean (Wang et al, 2008), cranberry beans (Wang et al, 2009), tea leaves (Nisha et al, 2011) and fava beans (Wang et al, 2012). Different types of cell wall degrading chitinases and glucanases have been successfully transferred to crops such as silver birch (Pappinen et al, 2002) and grapevine (Yamamoto et al, 2000).…”

“…Chitinases have seven classes (I-VII) (Neuhaus, 1999). However, most chitinases present in leguminous plants belong to class I-IV, because information about other three classes is not known yet (Wang et al, 2009). Class I chitinases are basic and consist of N-terminal cysteine rich chitin binding domain.…”