Complete amino acid sequence of an immunomodulatory protein, ling zhi-8 (LZ-8). An immunomodulator from a fungus, Ganoderma lucidium, having similarity to immunoglobulin variable regions.
The complete amino acid sequence of a novel immunomodulatory protein, ling zhi-8 (LZ-8), isolated from a fungus, Ganoderma lucidium (Kino, K., Yamashita, A., Yamaoka, K., Watanabe, J., Tanaka, S., Ko, K., Shimizu, K., and Tsunoo, H. (1989) J. Biol. Chem. 264, 472-478), was determined by protein sequencing. The polypeptide consists of 110 amino acid residues with an acetylated amino end and has a molecular mass of 12,420 Da including an amino-end blocking group. There is no attachment site for an Asn-linked oligosaccharide chain, consistent with the very low carbohydrate content of LZ-8. These results indicate that the native form of LZ-8 with a molecular mass of 24 kDa is a homodimer of the LZ-8 polypeptide whose sequence is described here. Furthermore, the LZ-8 chain shows considerable similarity to the variable region of immunoglobulin heavy chain both in its sequence and in its predicted secondary structure. The interesting possibility that LZ-8 is related to an ancestral protein of the immunoglobulin superfamily is also discussed.
Tanaka
S
S
Biochemical Genetics Division, Meiji Institute of Health Science, Kanagawa, Japan.
Ko
K
K
Kino
K
K
Tsuchiya
K
K
Yamashita
A
A
Murasugi
A
A
Sakuma
S
S
Tsunoo
H
H
D000276:Adjuvants, Immunologic; D000595:Amino Acid Sequence; D000818:Animals; D000954:Antigens, Surface; D002942:Circular Dichroism; D005656:Fungal Proteins; D006801:Humans; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000302:isolation & purification; D011124:Polyporaceae; D011487:Protein Conformation; D012689:Sequence Homology, Nucleic Acid; D018800:Thy-1 Antigens
D000276:Adjuvants, Immunologic; D000954:Antigens, Surface; D005656:Fungal Proteins; D007143:Immunoglobulin Heavy Chains; D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D010446:Peptide Fragments; D018800:Thy-1 Antigens; C061148:LZ-8 protein, Ganoderma lucidum