| Autor: |
Honjoh, Ken-ichi, Matsumoto, Hiroko, Shimizu, Hideyuki, Ooyama, Kanae, Tanaka, Kageyuki, Oda, Yuichi, Takata, Ryoji, Joh, Toshio, Suga, Koushirou, Miyamoto, Takahisa, Iio, Masayoshi, Hatano, Shoji |
| Jazyk: |
angličtina |
| Rok vydání: |
2000 |
| Předmět: |
|
| Zdroj: |
Bioscience, Biotechnology, and Biochemistry. 64(8):1656-1663 |
| ISSN: |
0916-8451 |
| Popis: |
The nucleotide sequence of hiC12, isolated as a cDNA clone of hardening-induced Chlorella (hiC) genes, was identified. The clone encodes a late embryogenesis abundant (LEA) protein having six repeats of a 11-mer amino acid motif, although in a slightly imperfect form. To overexpress the hiC61) and hiC12 genes, their coding regions were PCR amplified and subcloned into a pGEX-1λT vector. The HIC6 and HIC12 proteins were expressed as GST fusion proteins in E. coli, then purified. The two HIC proteins were found to be effective in protecting a freeze-labile enzyme, LDH, against freeze-inactivation. On a molar concentration basis, they were about 3.1×106 times more effective in protecting LDH than sucrose and as effective as BSA. Cryoprotection tests with five kinds of chain-shortened polypeptides, synthesized based on the 11-mer amino acid motif of the HIC6 protein showed that the cryoprotective activity decreased with a decrease in the repeating units of the 11-mer motif. In fact, cryoprotective activities of three kinds of single 11-mer amino acids were very low even at high concentrations. All the results suggested that the sufficiently repeated 11-mer motif is required for the cryoprotective activities of Chlorella LEA proteins. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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