A New Subtilisin-Like Proteinase from Roots of the Dandelion Taraxacum officinale Webb S. L.

A. M. Bogacheva^1*, G. N. Rudenskaya¹, A. Preusser¹, I. O. Tchikileva¹, Ya. E. Dunaevsky², B. N. Golovkin³, and V. M. Stepanov¹

¹Department of Natural Compounds, School of Chemistry, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (7-095) 939-3181; E-mail: annamb@genebee.msu.su

²Belozersky Institute of Physico-Chemical Biology, Lomonosov Moscow State University, Moscow, 119899 Russia; fax: (7-095) 939-3181

³Department of Tropical Plants, Botanical Garden, Russian Academy of Sciences, Moscow, 127276 Russia

^* To whom correspondence should be addressed.

Received December 1, 1998; Revision received May 11, 1999

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A serine proteinase from roots of Taraxacum officinale Webb S. L. was isolated by affinity chromatography and gel-filtration on Superose 6R using FPLC. The enzyme is a 67-kD glycoprotein containing 54% carbohydrate which we have named taraxalisin. The substrate specificity of taraxalisin toward synthetic peptides and oxidized insulin B-chain is comparable with that of cucumisin from Cucumis melo and the subtilisin-like serine proteinase macluralisin from Maclura pomifera. The proteinase is inactivated by DFP and PMSF. Taraxalisin exhibits maximal activity at pH 8.0. The pH range for stability of the enzyme is narrow--6.0-9.0. The temperature optimum for the subtilisin-like activity is 40°C. The N-terminal sequence of taraxalisin has 40% of its residues identical to those of subtilisin Carlsberg. Thus, the serine proteinase from dandelion roots is a member of the subtilisin family, which is evidently widespread in the plant kingdom.

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KEY WORDS: proteinases, subtilisins, taraxalisin, dandelion roots, isolation, properties

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