Preparation and Properties of Clostridium thermocellum Lichenase Deletion Variants and Their Use for Construction of Bifunctional Hybrid Proteins

K. A. Musiychuk^*, I. V. Goldenkova, R. M. Abdeev, N. S. Kobets, and E. S. Piruzian

Vavilov Institute of General Genetics, Russian Academy of Sciences, ul. Gubkina 3, Moscow, 117809 Russia; fax: (095) 132-8962; E-mail: kostyam@vigg.ru

^* To whom correspondence should be addressed.

Received April 10, 2000; Revision received June 14, 2000

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Major properties (pH and temperature optimum, stability) of lichenase (beta-1,3-1,4-glucanase) deletion variants from Clostridium thermocellum were comparatively studied. The deletion variant LicBM2 was used to create hybrid bifunctional proteins by fusion with sequences of the green fluorescent protein (GFP) from Aequorea victoria. The data show that in hybrid proteins both GFP and lichenase retain their major properties, namely, GFP remains a fluorescent protein and the lichenase retains activity and high thermostability. Based on the results of this investigation and results that have been obtained earlier, the use of the deletion variants of lichenase and the bifunctional hybrid proteins as reporter proteins is suggested.

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KEY WORDS: thermostable lichenase (beta-1,3-1,4-glucanase), green fluorescent protein (GFP), reporter systems, hybrid bifunctional proteins

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