Lipid transfer proteins from Brassica campestris and mung bean surpass mung bean chitinase in exploitability.
Antifungal peptides with a molecular mass of 9 kDa and an N-terminal sequence demonstrating remarkable similarity to those of nonspecific lipid transfer proteins (nsLTPs) were isolated from seeds of the vegetable Brassica campestris and the mung bean. The purified peptides exerted an inhibitory action on mycelial growth in various fungal species. The antifungal activity of Brassica and mung bean nsLTPs were thermostable, pH-stable, and stable after treatment with pepsin and trypsin. In contrast, the antifungal activity of mung bean chitinase was much less stable to changes in pH and temperature. Brassica LTP inhibited proliferation of hepatoma Hep G2 cells and breast cancer MCF 7 cells with an IC(50) of 5.8 and 1.6 microM, respectively, and the activity of HIV-1 reverse transcriptase with an IC(50) of 4 microM. However, mung bean LTP and chitinase were devoid of antiproliferative and HIV-1 reverse transcriptase inhibitory activities. In contrast to the mung bean LTP, which exhibited antibacterial activity, Brassica LTP was inactive. All three antifungal peptides lacked mitogenic activity toward splenocytes. These results indicate that the two LTPs have more desirable activities than the chitinase and that there is a dissociation between the antifungal and other activities of these antifungal proteins.
Lin
Peng
P
Department of Biochemistry, Faculty of Medicine, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
Xia
Lixin
L
Wong
Jack H
JH
Ng
T B
TB
Ye
Xiuyun
X
Wang
Shaoyun
S
Shi
Xiangzhu
X
D000595:Amino Acid Sequence; D000935:Antifungal Agents / Q000494:pharmacology*; D052179:Antigens, Plant / Q000302:isolation & purification / Q000494:pharmacology*; D001937:Brassica / Q000737:chemistry; D002352:Carrier Proteins / Q000302:isolation & purification / Q000494:pharmacology*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D002688:Chitinases / Q000494:pharmacology*; D019428:HIV Integrase Inhibitors / Q000032:analysis; D054303:HIV Reverse Transcriptase / Q000037:antagonists & inhibitors; D006358:Hot Temperature; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008969:Molecular Sequence Data; D027805:Phaseolus / Q000737:chemistry / Q000201:enzymology; D010940:Plant Proteins / Q000302:isolation & purification / Q000494:pharmacology*
D000935:Antifungal Agents; D052179:Antigens, Plant; D002352:Carrier Proteins; D019428:HIV Integrase Inhibitors; D010940:Plant Proteins; C511920:lipid transfer proteins, plant; D054303:HIV Reverse Transcriptase; D002688:Chitinases