The development of cysteine proteases in freesia corms during responses to chilling

✍ Scribed by Tetsuya Uchikoba; Shigeko Fukumoto; Michio Onjo; Michiko Okubo; Kazunari Arima; Hiroo Yonezawa

• Publisher: Elsevier Science
• Year: 2003
• Tongue: English
• Weight: 276 KB
• Volume: 28
• Category: Article
• ISSN: 0306-4565
• DOI: 10.1016/j.jtherbio.2003.07.001

✦ Synopsis

Freesia protease (FP)-A has been found in regular freesia corms (Kaneda et al., Biosci. Biotechnol. Biochem. 61 (1997) 1554). New corms were generated from original corms that were kept for several months at 4 C. In this study, two proteases (FP-B and FP-C) have been found to new corms kept for 6 months at 4 C, and have increased during new corms enlargement.

FPs were purified from the extracts of new corms, and the M r of those were 24k (A), 25k (B), and 24.5k (C) by SDS-PAGE, respectively.

The N-terminal sequences of FPs were identical to those of papain with respect to the conservative residues of cysteine protease. The sequence of FP-A was identical with those of FP-B within 20 residues of its N-terminal. It may be possible that FP-B was produced by some post-translational modifications from FP-A during the chilling. On the other hand, N-terminal sequence of FP-C was different from those of FP-A and FP-B. It was explained that FP-C was a new protease of freesia corm.