76
and the N-terminal sequence similar to those of angiosperm thaumatin-like proteins
and thaumatins and an inactive variant of the ubiquitin-conjugating enzyme. LAP
showed antifungal activity against Physalospora piricola and Mycosphaerella arachidicola, whereas in Rhizoctonia solani, Colletotrichum gossypii, and Coprinus
comatus, no effect was observed. Very low translation-inhibitory activity in a rabbit
reticulocyte lysate system, insignificant ribonuclease activity toward yeast transfer
RNA, and hemagglutinating activity toward rabbit erythrocytes were observed.
HIV-1 reverse transcriptase was inhibited with an IC 50 approximately of 5.2 nM. LAP
and lyophyllin showed a synergism in antifungal activity against Physalospora piricola (Lam and Ng 2001b).
It has been reported that some plant RIPs adversely affect mouse embryonic
development. Chan et al. (2010) reported for first the time on the teratogenicity of a
mushroom RIP; this protein isolated from Lyophyllum shimeji was called lyophyllin. After it was partially sequenced, the translation-inhibitory activity was determined. Its teratogenicity was evaluated by using a technique entailing microinjection
and postimplantation whole-embryo culture. Lyophyllin at a concentration as low as
50 μg/ml induced embryonic abnormalities during the period of organogenesis from
E8.5 to E9.5. When the lyophyllin concentration was raised, the number of abnormal embryos increased, the final somite number decreased, and the abnormalities
increased a lot. The affected embryonic structures was the cranial neural tube, forelimb buds, branchial arches, and body axis, while optic and otic placodes were less
affected. Lyophyllin at a concentration higher than 500 μg/ml also induced forebrain blisters within the cranial mesenchyme. The histological study of the abnormal embryos reported an increase of cell death associated with abnormal structures
indicating that cell death may be one of the underlying causes of teratogenicity of
the mushroom RIP.
A RIP was purified from fresh sclerotia of the edible mushroom Pleurotus tuberregium. This RIP was designated pleuturegin and inhibited translation in a cell-free
rabbit reticulocyte lysate system (IC 50 of 0.5 nM). N-Terminal sequence of pleuturegin was different from RIPs flammulin and velutin from Flammulina velutipes, hypsin from Hypsizygus marmoreus, and lyophyllin from Lyophyllum shimeji, the only
mushroom RIPs with known N-terminal sequences. The molecular weight of pleuturegin (38 kDa) was similar to that of flammulin (40 kDa) but larger than those of
velutin, hypsin, and lyophyllin (13.8, 20, and 20 kDa, respectively). Pleuturegin
lacked ribonuclease activity (Wang and Ng 2001a).
A novel RIP isolated from fresh fruiting bodies of the mushroom Hypsizygus
marmoreus designated as marmorin reported a molecular mass of 9.567 kDa.
Marmorin inhibited the proliferation of hepatoma Hep G2 cells (IC 50 of 0.15 μM)
and breast cancer MCF-7 cells (IC 50 of 5 μM), as well as HIV-1 reverse transcriptase
activity (IC 50 of 30 μM) and translation in the rabbit reticulocyte lysate system (IC 50
of 0.7 nM). Marmorin showed higher antiproliferative activity toward hepatoma
(HepG2) and breast cancer (MCF-7) cells than RIPs from hairy gourd, bitter gourd,
ridge gourd, garden pea, and the mushroom Flammulina velutipes, and similar
inhibitory potency toward HIV-1 reverse transcriptase with those mentioned above
with the exception of RIPS of ridge gourd and bitter gourd, because marmorin was
G. Díaz-Godínez and R. Díaz
and the N-terminal sequence similar to those of angiosperm thaumatin-like proteins
and thaumatins and an inactive variant of the ubiquitin-conjugating enzyme. LAP
showed antifungal activity against Physalospora piricola and Mycosphaerella arachidicola, whereas in Rhizoctonia solani, Colletotrichum gossypii, and Coprinus
comatus, no effect was observed. Very low translation-inhibitory activity in a rabbit
reticulocyte lysate system, insignificant ribonuclease activity toward yeast transfer
RNA, and hemagglutinating activity toward rabbit erythrocytes were observed.
HIV-1 reverse transcriptase was inhibited with an IC 50 approximately of 5.2 nM. LAP
and lyophyllin showed a synergism in antifungal activity against Physalospora piricola (Lam and Ng 2001b).
It has been reported that some plant RIPs adversely affect mouse embryonic
development. Chan et al. (2010) reported for first the time on the teratogenicity of a
mushroom RIP; this protein isolated from Lyophyllum shimeji was called lyophyllin. After it was partially sequenced, the translation-inhibitory activity was determined. Its teratogenicity was evaluated by using a technique entailing microinjection
and postimplantation whole-embryo culture. Lyophyllin at a concentration as low as
50 μg/ml induced embryonic abnormalities during the period of organogenesis from
E8.5 to E9.5. When the lyophyllin concentration was raised, the number of abnormal embryos increased, the final somite number decreased, and the abnormalities
increased a lot. The affected embryonic structures was the cranial neural tube, forelimb buds, branchial arches, and body axis, while optic and otic placodes were less
affected. Lyophyllin at a concentration higher than 500 μg/ml also induced forebrain blisters within the cranial mesenchyme. The histological study of the abnormal embryos reported an increase of cell death associated with abnormal structures
indicating that cell death may be one of the underlying causes of teratogenicity of
the mushroom RIP.
A RIP was purified from fresh sclerotia of the edible mushroom Pleurotus tuberregium. This RIP was designated pleuturegin and inhibited translation in a cell-free
rabbit reticulocyte lysate system (IC 50 of 0.5 nM). N-Terminal sequence of pleuturegin was different from RIPs flammulin and velutin from Flammulina velutipes, hypsin from Hypsizygus marmoreus, and lyophyllin from Lyophyllum shimeji, the only
mushroom RIPs with known N-terminal sequences. The molecular weight of pleuturegin (38 kDa) was similar to that of flammulin (40 kDa) but larger than those of
velutin, hypsin, and lyophyllin (13.8, 20, and 20 kDa, respectively). Pleuturegin
lacked ribonuclease activity (Wang and Ng 2001a).
A novel RIP isolated from fresh fruiting bodies of the mushroom Hypsizygus
marmoreus designated as marmorin reported a molecular mass of 9.567 kDa.
Marmorin inhibited the proliferation of hepatoma Hep G2 cells (IC 50 of 0.15 μM)
and breast cancer MCF-7 cells (IC 50 of 5 μM), as well as HIV-1 reverse transcriptase
activity (IC 50 of 30 μM) and translation in the rabbit reticulocyte lysate system (IC 50
of 0.7 nM). Marmorin showed higher antiproliferative activity toward hepatoma
(HepG2) and breast cancer (MCF-7) cells than RIPs from hairy gourd, bitter gourd,
ridge gourd, garden pea, and the mushroom Flammulina velutipes, and similar
inhibitory potency toward HIV-1 reverse transcriptase with those mentioned above
with the exception of RIPS of ridge gourd and bitter gourd, because marmorin was
G. Díaz-Godínez and R. Díaz