Table 1.
Thionins and derived peptides: sequence, net charge at pH 7.0, and biological activity. Cysteine residues are shown in red, substituted amino acids are highlighted in cyan, and modified amino acids are highlighted in green. B—α-aminobutyric acid, c—D-cysteine, and X—homocysteine. Gaps (−) were introduced to improve the alignment. Note: nd—not determined.
| Peptide | Amino Acid Sequence | Net Charge at pH 7.0 |
|---|---|---|
| Antimicrobial Activity and Toxicity | Reference | |
| α-Purothionin | KS CC RSTLGRN C YNL C RARG--AQKL C AGV C R C KISSGLS C PKGFPK | +10 |
| MIC (minimal inhibition concentration) = 3 μg/mL and MBC (minimal bactericidal concentration) = 6 μg/mL against Pseudomonas solanacearum; MIC = 6 μg/mL and MBC = 12 μg/mL against Xanthomonas phaseoli. | [33] | |
| β-Purothionin | KS CC KSTLGRN C YNL C RARG--AQKL C ANV C R C KLTSGLS C PKDFPK | +9 |
| Complete growth suppression of yeasts at a concentration of 4.7 μg/mL. Lethal to mice within 40 min when administered at 0.1 mg. | [32] | |
| MIC = 1.5 μg/mL and MBC = 1.5 μg/mL against P. solanacearum; MIC = 12 μg/mL and MBC = 25 μg/mL against X. phaseoli. | [33] | |
| Acetyl derivative of β-purothionin | K S CC K STLGRN C YNL C RARG--AQKL C ANV C R C K LTSGLS C PKDFPK | nd |
| No toxity towards yeast cells at a concentration of 11.0 μg/mL. | [32] | |
| Succinyl derivative of β-purothionin | K S CC K STLGRN C YNL C RARG--AQKL C ANV C R C K LTSGLS C PKDFPK | nd |
| No toxity towards yeast cells at a concentration of 10.0 μg/mL. | [32] | |
| Iodinated derivative of β-purothionin | KS CC KSTLGRN C Y NL C RARG--AQKL C ANV C R C KLTSGLS C PKDFPK | nd |
| No toxity towards yeast cells at a concentration of 10.0 μg/mL. Scarcely lethal to mice when administered at 10.0 mg. | [32] | |
| Nitrated derivative of β-purothionin | KS CC KSTLGRN C Y NL C RARG--AQKL C ANV C R C KLTSGLS C PKDFPK | nd |
| Weakly toxic toward yeast cells at a concentration of 12.6 μg/mL. Toward mice, the efficiency is less than 30% compared to that of native purothinin. | [32] | |
| Pp-TH | KS CC RNTWARN C YNV C RLPGTISREI C AKK C D C KIISGTT C PSDYPK | +6 |
| For natural Pp-TH: | ||
| 50% hemolysis at 20 μg/mL. IC50 (concentration required for 50% growth inhibition) = 5.0 μg/mL against mouse B16 melanoma cells; IC50 = 14 μg/mL against HeLa cells; 100% lethal to mice within 4.5 min when administered at 100 μg. | [34] | |
| EC50 (Effective concentration for 50% inhibition) > 20 μM (>20 μM) against Rhizobium meliloti; EC50 = 3.1 μM (3.67 μM) against Xanthamonas campestris pv. campestris; EC50 = 1.7 μM against X. campestris pv. translucens; EC50 = 0.48 (0.23 μM) μM against Clavibacter michiganensis subsp. sepedonicus C5; EC50 = 0.43 μM (0.38 μM) against Fusarium oxysporum f. sp. conglutinans; EC50 = 0.7 μM against Plectosphaerella cucumerina; EC50 = 2.2 μM against Botrytis cinerea; | [35], the figures in parentheses [36] | |
| For synthetic Pp-TH: EC50 > 20 μM against R. meliloti; EC50 = 2.9 μM against X. campestris pv. campestris; EC50 = 1.4 μM against X. campestris pv. translucens; EC50 = 0.48 μM against C. michiganensis; EC50 = 0.33 μM against F. oxysporum f. sp. conglutinans; EC50 = 0.8 μM against P. cucumerina; |
[35] | |
| EC50 > 20 μM against R. meliloti; EC50 = 3.65 μM against X. campestris; EC50 = 0.30 μM against C. michiganensis; EC50 = 0.36 μM against P. cucumerina; EC50 = 0.32 μM against B. cinerea. | [37] | |
| Iodinated derivative of Pp-TH | KS CC RNTWARN C Y NV C RLPGTISREI C AKK C D C KIISGTT C PSDYPK | nd |
| 0% hemolysis at 20 μg/mL. No activity against mouse B16 melanoma and HeLa cells at 100 μg/mL; Non-lethal to mice when administered at 100 μg. | [34] | |
| Pp-TH(D32R) or PpTHR or TH32R | KS CC RNTWARN C YNV C RLPGTISREI C AKK C R C KIISGTT C PSDYPK | +8 |
| EC50 = 3.3 μM (3.8 μM) against R. meliloti; EC50 = 1.2 μM (0.38 μM) against X. campestris pv. campestris; EC50 = 0.8 μM against X. campestris pv. translucens; EC50 = 0.38 μM (0.23 μM) against C. michiganensis subsp. sepedonicus C5; EC50 = 0.73 μM (1.52 μM) against F. oxysporum f. sp. conglutinans; EC50 = 1.25 μM against P. cucumerina; EC50 = 2.5 μM against B. cinerea; | [35], the figures in parentheses [36] | |
| EC50 = 0.8 μM against R. meliloti; EC50 = 0.3 μM against X. campestris; EC50 = 0.37 μM against C. michiganensis; EC50 = 0.36 μM against P. cucumerina; EC50 = 0.80 μM against B. cinerea. | [37] | |
| PpTH(3-41) | -- CC RNTWARN C YNV C RLPGTISREI C AKK C D C KIISGTT C | +5 |
| EC50 > 20 μM against R. meliloti; EC50 = 7.5 μM against X. campestris pv. campestris; EC50 = 0.18 μM against C. michiganensis subsp. sepedonicus C5; EC50 = 1.73 μM against F. oxysporum f. sp. conglutinans. | [36] | |
| PpTHR(3-41) | -- CC RNTWARN C YNV C RLPGTISREI C AKK C R C KIISGTT C | +7 |
| EC50 = 5.3 μM against R. meliloti; EC50 = 3.27 μM against X. campestris pv. campestris; EC50 = 0.21 μM against C. michiganensis subsp. sepedonicus C5; EC50 = 2.5 μM against F. oxysporum f. sp. conglutinans. | [36] | |
| PpTH(7-32) | ------ TWARN C YNV C RLPGTISREI C AKK C D | +3 |
| EC50 > 20 μM against R. meliloti; EC50 > 20 μM against X. campestris pv. campestris; EC50 = 0.63 μM against C. michiganensis subsp. sepedonicus C5; EC50 = 1.8 μM against F. oxysporum f. sp. conglutinans. | [36] | |
| PpTH(7-32)b (disulfide bridges C1-C2 and C3-C4) | ------ TWARN C YNV C RLPGTISREI C AKK C D | +3 |
| EC50 > 20 μM against R. meliloti; EC50 > 20 μM against X. campestris pv. campestris; EC50 = 1.8 μM against C. michiganensis subsp. sepedonicus C5; EC50 > 20 μM against F. oxysporum f. sp. conglutinans. | [36] | |
| PpTHR(7-32) or TH(7-32R) | ------ TWARN C YNV C RLPGTISREI C AKK C R | +5 |
| EC50 = 4 μM against R. meliloti; EC50 = 7.2 μM against X. campestris pv. campestris; EC50 = 1.58 μM against C. michiganensis subsp. sepedonicus C5; EC50 = 0.5 μM against F. oxysporum f. sp. conglutinans; | [36] | |
| EC50 = 4 μM against R. meliloti; EC50 = 4.6 μM against X. campestris; EC50 = 0.80 μM against C. michiganensis; EC50 = 7.5 μM against P. cucumerina; EC50 = 0.80 μM against B. cinerea. | [37] | |
| PpTH(24-32) | ----------------------- REI C AKK C D | +1 |
| EC50 > 20 μM against R. meliloti; EC50 > 20 μM against X. campestris pv. campestris; EC50 > 20 μM against C. michiganensis subsp. sepedonicus C5; EC50 > 20 μM against F. oxysporum f. sp. conglutinans. | [36] | |
| PpTHR(24-32) or TH(24-32R) | ----------------------- REI C AKK C R | +3 |
| EC50 > 20 μM against R. meliloti; EC50 > 20 μM against X. campestris pv. campestris; EC50 = 16 μM against C. michiganensis subsp. sepedonicus C5; EC50 > 20 μM against F. oxysporum f. sp. conglutinans; | [36] | |
| EC50 > 50 μM against R. meliloti; EC50 > 50 μM against X. campestris; EC50 = 21 μM against C. michiganensis; EC50 = 20 μM against P. cucumerina; EC50 = 3.50 μM against B. cinerea. | [37] | |
| TH(24-32R)Abu | ----------------------- REIBAKKBR | nd |
| EC50 > 50 μM against R. meliloti; EC50 > 50 μM against X. campestris; EC50 = 5.13 μM against C. michiganensis; EC50 = 15.67 μM against P. cucumerina; EC50 = 4.10 μM against B. cinerea. | [37] | |
| TH(24-32R)cC | ----------------------- REIcAKK C R | nd |
| EC50 > 50 μM against R. meliloti; EC50 > 50 μM against X. campestris; EC50 = 0.90 μM against C. michiganensis; EC50 = 0.80 μM against P. cucumerina; EC50 = 0.55 μM against B. cinerea. | [37] | |
| TH(24-32R)cH | ----------------------- REIcAKKXR | nd |
| EC50 > 50 μM against R. meliloti; EC50 > 50 μM against X. campestris; EC50 = 0.90 μM against C. michiganensis; EC50 = 0.78 μM against P. cucumerina; EC50 = 0.40 μM against B. cinerea. | [37] | |
| PpTH(7-19) | ------ TWARN C YNV C RLP | +2 |
| EC50 > 20 μM against R. meliloti; EC50 > 20 μM against X. campestris pv. campestris; EC50 = 15 μM against C. michiganensis subsp. sepedonicus C5; EC50 > 20 μM against F. oxysporum f. sp. conglutinans; | [36] | |
| EC50 > 50 μM against R. meliloti; EC50 > 50 μM against X. campestris; EC50 > 50 μM against C. michiganensis; EC50 = 29 μM against P. cucumerina; EC50 = 5.50 μM against B. cinerea. | [37] | |
| PpTH(7-19)Abu | ------ TWARNBYNVBRLP | nd |
| EC50 > 50 μM against R. meliloti; EC50 > 50 μM against X. campestris; EC50 = 3.27 μM against C. michiganensis; EC50 = 3.97 μM against P. cucumerina; EC50 = 1.60 μM against B. cinerea. | [37] | |
| PpTH(7-19)cC | ------ TWARNcYNV C RLP | nd |
| EC50 > 50 μM against R. meliloti; EC50 = 29.33 μM against X. campestris; EC50 = 0.51 μM against C. michiganensis; EC50 = 2.77 μM against P. cucumerina; EC50 = 0.20 μM against B. cinerea. | [37] | |
| PpTH(7-19)cH | ------ TWARNcYNVXRLP | nd |
| EC50 > 50 μM against R. meliloti; EC50 = 18.33 μM against X. campestris; EC50 = 0.74 μM against C. michiganensis; EC50 = 3.50 μM against P. cucumerina; EC50 = 0.19 μM against B. cinerea. | [37] | |
| PpTH(15−28) | -------------- V C RLPGTISREI C A | +1 |
| EC50 > 20 μM against R. meliloti; EC50 > 20 μM against X. campestris pv. campestris; EC50 > 20 μM against C. michiganensis subsp. sepedonicus C5; EC50 > 20 μM against F. oxysporum f. sp. conglutinans. | [36] | |
| TH(7-19)(24-32R) | ------ TWARN C YNV C RLP - + - REI C AKK C R | +2 and +3 |
| EC50 = 2.07 μM against R. meliloti; EC50 = 1.03 μM against X. campestris; EC50 = 0.03 μM against C. michiganensis; EC50 = 0.16 μM against P. cucumerina; EC50 = 0.08 μM against B. cinerea. | [37] | |
| Viscotoxin A3 | KS CC PNTTGRNIYNA C RLTGA-PRPT C AKLSG C KIISGST C PSDYPK | +6 |
| ED50 (concentration of substance inhibiting 3H-thymidine incorporation 50%) = 0.31 μg/mL against Yoshida sarcoma cells; | [38] | |
| Can penetrate into the model monolayer membrane (critical surface pressure πc ≤ 39.6 μN/m). | [39] | |
| Viscotoxin A2 | KS CC PNTTGRNIYNT C RFGGG-SREV C ASLSG C KIISAST C PSYPDK | +4 |
| ED50 = 1.06 μg/mL against Yoshida sarcoma cells; | [38] | |
| Can penetrate into the model monolayer membrane (critical surface pressure πc ≤ 32.3 μN/m). | [39] | |
| Viscotoxin A1 | KS CC PSTTGRNIYNT C RLTGS-SRET C AKLSG C KIISAST C PSNYPK | +6 |
| ED50 = 0.87 μg/mL against Yoshida cells. | [38] | |
| Viscotoxin B | KS CC PNTTGRNIYNT C RLGGG-SRER C ASLSG C KIISAST C PSDYPK | +5 |
| ED50 = 4.58 μg/mL against Yoshida sarcoma cells; | [38] | |
| Penetration into the model monolayer membrane is unlikely (critical surface pressure πc ≤ 27.0 μN/m). | [39] |