title: Effect of replacing the aspartic acid/glutamic acid residues of bullfrog sialic acid binding lectin with asparagine/glutamine and arginine on the inhibition of cell proliferation in murine leukemia P388 cells.
abstract: The sialic acid binding lectin from bullfrog oocytes (cSBL) is known to have anti-tumor activity. In a previous report, to elucidate the relationship between the net charge and anti-tumor activity of cSBL, we examined the effect of chemical modifications of cSBL with a water-soluble carbodiimide in the presence of various nucleophiles. The results suggested that the anti-tumor activity and internalization into tumor cells increased with an increase in the net charge of cSBL. However, in the chemically modified cSBL, a modification site was observed on average in two of the carboxyl groups of cSBL. To confirm these previous results and to determine which modified carboxyl group contributes to the increase in anti-tumor activity, we prepared mutants with substitutions of Asn/Gln and Arg at three acidic amino acid residues of cSBL and studied their anti-tumor activity and internalization efficiency. The results showed the enhancing effect of charge on anti-tumor activity and internalization, and suggested that the replacement of D24 and E88 of cSBL with arginine is more effective than that of E97. The double mutant D24RE88R showed comparable anti-tumor activity to the ethylenediamine-modified cSBL reported previously. The mutant was well-characterized as a pure cSBL derivative suitable for studying the mechanism of the anti-tumor action of cSBL.
authors.affiliation: Department of Microbiology, Hoshi College of Pharmacy, Tokyo, Japan.
authors.forename: Yuko
authors.initials: Y
authors.lastname: Ogawa
authors.forename: Masanori
authors.initials: M
authors.lastname: Iwama
authors.forename: Kazuko
authors.initials: K
authors.lastname: Ohgi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Tsuji
authors.forename: Masachika
authors.initials: M
authors.lastname: Irie
authors.forename: Tadashi
authors.initials: T
authors.lastname: Itagaki
authors.forename: Hiroko
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Norio
authors.initials: N
authors.lastname: Inokuchi
mesh_terms: D019943:Amino Acid Substitution / Q000235:genetics; D000818:Animals; D000970:Antineoplastic Agents / Q000494:pharmacology; D001120:Arginine / Q000378:metabolism*; D001216:Asparagine / Q000378:metabolism*; D001224:Aspartic Acid / Q000378:metabolism*; D002455:Cell Division / Q000502:physiology; D002942:Circular Dichroism; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000378:metabolism; D018698:Glutamic Acid / Q000378:metabolism*; D018922:HL-60 Cells; D006801:Humans; D037102:Lectins / Q000378:metabolism; D007941:Leukemia P388 / Q000378:metabolism; D051379:Mice; D008856:Microscopy, Fluorescence; D016297:Mutagenesis, Site-Directed; D019158:N-Acetylneuraminic Acid / Q000378:metabolism*; D011892:Rana catesbeiana; D012260:Ribonucleases / Q000037:antagonists & inhibitors
chemical_list: D000970:Antineoplastic Agents; D037102:Lectins; D001224:Aspartic Acid; D018698:Glutamic Acid; D001216:Asparagine; D001120:Arginine; D012260:Ribonucleases; D019158:N-Acetylneuraminic Acid