Actinohivin, a novel anti-HIV protein from an actinomycete that inhibits syncytium formation: isolation, characterization, and biological activities.
Blocking human immunodeficiency virus (HIV) entry into target cells is an important goal of HIV and acquired immune deficiency syndrome (AIDS) therapies. We have searched for anti-HIV substances from microorganisms using a syncytium formation assay system constructed with HeLa/CD4/Lac-Z and HeLa/T-env/Tat cells. We discovered a novel anti-HIV protein that inhibits syncytium formation, designated as actinohivin, from a cultured broth of a soil isolate, actinomycete strain K97-0003. ESI mass spectrometry of actinohivin isolated from the culture filtrate showed an ion with molecular mass of 12,520.3 Da. The amino acid sequence was determined by N-terminal Edman degradation of the intact protein and peptide fragments formed by endoproteinase digestions. Actinohivin consists of a 114-amino-acid chain that exhibits internal sequence triplication. Actinohivin inhibited both T-cell and macrophage tropic syncytium formation, with IC(50) values of 60 and 700 nM, respectively, and the cytopathic effect of HIV-1(IIIB) in MT-4 cells, with IC(50) value of 230 nM.
Chiba
H
H
School of Pharmaceutical Sciences, Kitasato University, 5-9-1 Shirokane, Minato-ku, Tokyo, 108-8641, Japan.
Inokoshi
J
J
Okamoto
M
M
Asanuma
S
S
Matsuzaki Ki
Iwama
M
M
Mizumoto
K
K
Tanaka
H
H
Oheda
M
M
Fujita
K
K
Nakashima
H
H
Shinose
M
M
Takahashi
Y
Y
Omura
S
S
D000192:Actinomycetales / Q000737:chemistry* / Q000235:genetics / Q000648:ultrastructure; D000595:Amino Acid Sequence; D019380:Anti-HIV Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000494:pharmacology*; D003588:Cytopathogenic Effect, Viral / Q000187:drug effects; D015726:Giant Cells / Q000187:drug effects / Q000821:virology; D015658:HIV Infections / Q000517:prevention & control; D015497:HIV-1 / Q000187:drug effects / Q000472:pathogenicity; D006367:HeLa Cells; D006801:Humans; D008264:Macrophages / Q000187:drug effects / Q000821:virology; D008855:Microscopy, Electron, Scanning; D008969:Molecular Sequence Data; D008970:Molecular Weight; D017386:Sequence Homology, Amino Acid; D021241:Spectrometry, Mass, Electrospray Ionization; D013601:T-Lymphocytes / Q000187:drug effects / Q000821:virology
D019380:Anti-HIV Agents; D001426:Bacterial Proteins; C424136:actinohivin protein, actinomycete