Extracellular Alkaline Proteinase of Colletotrichum gloeosporioides

---

Ya. E. Dunaevsky^1*, A. R. Matveeva², G. A. Beliakova², V. I. Domash³, and M. A. Belozersky¹

¹Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, 119992 Moscow, Russia; fax: (495) 939-3181; E-mail: dun@belozersky.msu.ru

²Faculty of Biology, Lomonosov Moscow State University, 119992 Moscow, Russia

³Kuprevich Institute of Experimental Botany, National Academy of Sciences of Belarus, 220141 Minsk, Belarus

^* To whom correspondence should be addressed.

Received October 2, 2006; Revision received November 7, 2006

---

The main proteinase of the filamentous fungus Colletotrichum gloeosporioides causing anthracnoses and serious problems for production and storage of agricultural products has molecular mass of 57 kD and was purified more than 200-fold to homogeneity with the yield of 5%. Maximal activity of the proteinase is at pH 9.0-10.0, and the enzyme is stable at pH 6.0-11.5 (residual activity not less than 70%). The studied enzyme completely kept its activity to 55°C, with a temperature optimum of 45°C. The purified C. gloeosporioides proteinase is stable at alkaline pH values, but rapidly loses its activity at pH values lower than 5.0. Addition of bovine serum albumin stabilizes the enzyme under acidic conditions. Data on inhibitor analysis and substrate specificity of the enzyme allow its classification as a serine proteinase of subtilisin family. It is demonstrated that the extracellular proteinase of C. gloeosporioides specifically effects plant cell wall proteins. It is proposed that the studied proteinase - via hydrolysis of cell wall - provides for penetration of the fungus into the tissues of the host plant.

---

KEY WORDS: fungi, Colletotrichum gloeosporioides, plants, serine proteinase, pathogens

DOI: 10.1134/S0006297907030145

---