【For INTERNATIONAL COLLABORATIVE RESEARCH 2019】

DATE: Day 13Month 05

Year 2020

SUMMARY of
2019 RESEARCH RESULTS REPORTFor International Collaborative Research with IPR, Osaka University
Research Title
Development of a new method to conjugate the defensin
peptide to the carrier protein P64K using the thioester
chemistry.
Hilda Elisa Garay Pérez (1) and David Diago Abreu (2)ApplicantName
Affiliation

Center for Genetic Engineering and Biotechnology (CIGB)

Present Title(1)Senior Researcher. Head of Synthetic Peptides Group.
(2) Head of Analytical and Purification Laboratory on Peptides

Research Collaborator (Host PI)

GroupHironobu Hojo (Professor)

Summary
Actually, is a big problem in a worldwide and in Cuba the plant diseases caused by different
microorganism, focused the impact in crop production. As an effort to get a solution for disease
control, the researchers have identified the plant defensins as a good possibility. Plant defensins are
small, cysteine-rich peptides, which inhibit the growth of a wide range of microorganisms and arepart of the defense mechanisms of plants against diseases. This defensin was isolated from a plantand develops a strong anti- microbe activity in vitro and ex vitro against important bacteria, fungus
and oomycetes pathogens. Herewith, the constitutive expression of this defensin in transgenic plants
increased the resistance to many plant diseases with high economic impact. An important issue is theproduction of mono- and polyclonal antiserum that would specifically detect the recombinant
defensin from transgenic soybean lines. The low immunogenicity of simple peptide is a main
problem to generate immune response against these molecules. The problem presented can be solved
with the use of adequate systems of presentation to the immune system, which allows an increase in
the levels of induced antibodies and their functionality. Conjugation to carrier proteins, presentationof the antigenic sequence by multimerization by linear polymerization, strong adjuvants likerecombinant cytokines, conjugation to polysaccharides and the use of multiple antigen peptides aresome of successfully strategies.
Currently at CIGB; we generate antibodies against defensin using the conventional protocol for
conjugation using Succinic Anhydride- Carbodiimide Method to P64K. Could be an attractive
methodology conjugate the defensing to a carrier protein using the thioester chemistry to generate
effective immune response and compare it with the response obtained by previously protocol-Different methods for P64K activation and conjugation studies using a model peptide wereperformed. The results obtained were not successful.
-Different methods for Dendrimer (as a carrier protein model) activation and reaction with
2-aminoethanol as a conjugation model were performed. The results obtained were not successful.
-Different methods for Dendrimer (as a carrier protein model) activation and reaction withMetoxiglicin as a conjugation strategy were performed. The results obtained were not successful.
The activation and conjugation methods studied were not successful, therefore is necessary toperform additional studies in order to achieve the desired results. The MeOGly methodology could
be an alternative to obtain the conjugation of defensin peptide to P64K.
*Deadline: May 15, 2020
*Please submit it to E-mail: tanpakuken-kyoten@office.osaka-u.ac.jp.
*Please describe this summary within 1 sheet. Please DON’T add some sheets.
*This summary will be published on the web.