Next Article in Journal / Special Issue
Comments on Ekino et al. Cloning and Characterization of a Unique Cytotoxic Protein Parasporin-5 Produced by Bacillus thuringiensis A1100 Strain. Toxins 2014, 6, 1882–1895
Previous Article in Journal
Biodegradation of Ochratoxin A by Bacterial Strains Isolated from Vineyard Soils
Previous Article in Special Issue
Bacillus thuringiensis Toxins: An Overview of Their Biocidal Activity
 
 
Font Type:
Arial Georgia Verdana
Font Size:
Aa Aa Aa
Line Spacing:
Column Width:
Background:
Reply

Response to Leopoldo Palma. Comments on Ekino et al. Cloning and Characterization of a Unique Cytotoxic Protein Parasporin-5 Produced by Bacillus thuringiensis A1100 Strain. Toxins 2014, 6, 1882–1895

1
Department of Applied Microbial Technology, Faculty of Biotechnology and Life Science, Sojo University, 4-22-1 Ikeda, Kumamoto 860-0082, Japan
2
Biotechnology and Food Research Institute, Fukuoka Industrial Technology Center, 1465-5 Aikawa-machi, Kurume, Fukuoka 839-0861, Japan
3
Department of Bioscience and Bioinfomatics, Kyushu Institute of Technology, Iizuka, Fukuoka 820-8502, Japan
4
Graduate School of Agriculture, Kyushu University, Fukuoka 812-8581, Japan
*
Author to whom correspondence should be addressed.
Toxins 2015, 7(12), 5096-5097; https://doi.org/10.3390/toxins7124866
Submission received: 18 November 2015 / Accepted: 19 November 2015 / Published: 27 November 2015
(This article belongs to the Special Issue Bacillus thuringiensis Toxins)
I appreciate the thoughtful comments from Dr. Leopoldo Palma [1] on our research about cytotoxic protein parasporin-5 produced by Bacillus thuringiensis (BT) A1100 strain [2]. First of all, the term parasporin is defined as “Bacillus thuringiensis and related bacterial parasporal proteins that are non-hemolytic but capable of preferentially killing cancer cells” [3,4]. The definition does not refer to insecticidal activity. Mizuki et al. carried out a large-scale screening of BT strains for the new biological activity, that is, cytocidal activity to human cancer cells with non-hemolytic activities [5]. In this study, 1744 BT strains were investigated not only for cytocidal activity but also for insecticidal activities against 11 species of five orders (Lepidoptera, Diptera, Orthoptera, Dictyoptera, and Isoptera). As a result, 42 cytocidal BT strains, parasporin producers, have been discovered, all of which have non-insecticidal activities as far as tested. Further, the A1100 strain in our study was not toxic to the above 11 species. However, the insecticidal activity that we have studied was limited. Based on the above definition of parasporin, we do not deny the possibility that parasporins have insecticidal activity. Known parasporins might have insecticidal activity and novel insecticidal parasporins may be discovered. Further interesting research will clarify this unknown parasporin world.

Conflicts of Interest

The authors declare no conflict of interest.

References

  1. Palma, L. Comments on Ekino et al. Cloning and Characterization of a Unique Cytotoxic Protein Parasporin-5 Produced by Bacillus thuringiensis A1100 Strain. Toxins 2014, 6, 1882–1895. Toxins 2015, 7. [Google Scholar] [CrossRef]
  2. Ekino, K.; Okumura, S.; Ishikawa, T.; Kitada, S.; Saitoh, H.; Akao, T.; Oka, T.; Nomura, Y.; Ohba, M.; Shin, T.; et al. Cloning and characterization of a unique cytotoxic protein parasporin-5 produced by Bacillus thuringiensis A1100 strain. Toxins 2014, 6, 1882–1895. [Google Scholar] [CrossRef] [PubMed]
  3. Katayama, H.; Yokota, H.; Akao, T.; Nakamura, O.; Ohba, M.; Mekada, E.; Mizuki, E. Parasporin-1, a novel cytotoxic protein to human cells from non-insecticidal parasporal inclusions of Bacillus thuringiensis. J. Biochem. 2005, 137, 17–25. [Google Scholar] [CrossRef] [PubMed]
  4. Ohba, M.; Mizuki, E.; Crickmore, N.; Coté, J.-C.; Nagamatsu, Y.; Kitada, S.; Sakai, H.; Harata, K.; Shin, T.; Okumura, S. Parasporin Nomenclature. Available online: http://parasporin.fitc.pref.fukuoka.jp/ (accessed on 20 November 2015).
  5. Mizuki, E.; Ohba, M.; Akao, T.; Yamashita, S.; Saitoh, H.; Park, Y.S. Unique activity associated with non-insecticidal Bacillus thuringiensis parasporal inclusions: In vitro cell-killing action on human cancer cells. J. Appl. Microbiol. 1999, 86, 477–486. [Google Scholar] [CrossRef] [PubMed]

Share and Cite

MDPI and ACS Style

Ekino, K.; Okumura, S.; Ishikawa, T.; Kitada, S.; Saitoh, H.; Akao, T.; Oka, T.; Nomura, Y.; Ohba, M.; Shin, T.; et al. Response to Leopoldo Palma. Comments on Ekino et al. Cloning and Characterization of a Unique Cytotoxic Protein Parasporin-5 Produced by Bacillus thuringiensis A1100 Strain. Toxins 2014, 6, 1882–1895. Toxins 2015, 7, 5096-5097. https://doi.org/10.3390/toxins7124866

AMA Style

Ekino K, Okumura S, Ishikawa T, Kitada S, Saitoh H, Akao T, Oka T, Nomura Y, Ohba M, Shin T, et al. Response to Leopoldo Palma. Comments on Ekino et al. Cloning and Characterization of a Unique Cytotoxic Protein Parasporin-5 Produced by Bacillus thuringiensis A1100 Strain. Toxins 2014, 6, 1882–1895. Toxins. 2015; 7(12):5096-5097. https://doi.org/10.3390/toxins7124866

Chicago/Turabian Style

Ekino, Keisuke, Shiro Okumura, Tomoyuki Ishikawa, Sakae Kitada, Hiroyuki Saitoh, Tetsuyuki Akao, Takuji Oka, Yoshiyuki Nomura, Michio Ohba, Takashi Shin, and et al. 2015. "Response to Leopoldo Palma. Comments on Ekino et al. Cloning and Characterization of a Unique Cytotoxic Protein Parasporin-5 Produced by Bacillus thuringiensis A1100 Strain. Toxins 2014, 6, 1882–1895" Toxins 7, no. 12: 5096-5097. https://doi.org/10.3390/toxins7124866

Article Metrics

Back to TopTop