Japan As Represented by Director-general of National Institute of Infectious Diseases

Osaka Prefecture University Public Corporation

Medical Biological Laboratories Co., Ltd.

The Chemo-sero-therapeutic Research Institute

Institute for Antibodies Co., Ltd.

Juridical Foundation the Chemo-sero-therapeutic Research Institute

Motohide Takahashi

Yoshikazu Kurosawa

Gene Kurosawa

Kimiyasu Shiraki

Yoshinobu Okuno

Sachio Okuda

Yoshitaka Iba

Yasushi Torii

Yasushi Akahori

Tetsuhiro Harakawa

Hirotoshi Nakano

Ryuji Kaji

Shunji Kozaki

Yoshitaka Goto

Masachika Azuma

Midori Shinohara

Kazuhiko Morino

Takashi Sakamoto

Tomoko Kohda

Masafumi Mukamoto

Setsuji Ishida

Akihiro Ginnaga

The present invention relates to a method for quantitatively measuring the muscular relaxing activity of a neurotoxin. Specifically, based on an extent of the activity of muscular relaxation of a neurotoxin from bacteria of, the present invention relates to a method for quantification of the efficacy (potential and/or diffusion reaction) of a neurotoxin comprising the following steps of: (a) administering a neurotoxin to the hind leg muscle of one of hind legs of a non-human mammal; (b) applying electric stimulus to said non-human mammal; (c) measuring a compound muscle action potential (CMAP) by contraction of said hind leg muscle to which the neurotoxin is administered and/or of the hind leg muscle of the other hind leg to which the neurotoxin is not administered; and (d) taking amplitude data from the compound muscle action potential (CMAP) obtained by the measurement in step (c) and analyzing an extent of a decrease in amplitude to thereby quantify the efficacy of the muscular relaxing activity by the neurotoxin. In contrast to the mouse LDcurrently used as a potential unit of a botulinum toxin which is measurable at a level of only several units, the quantification method of the efficacy of a neurotoxin of the present invention allows for measurement at a level of as low as 0.01 to 1 unit and hence is a method with a high sensitivity, reproducibility and accuracy.

Method for quantification of neurotoxin

Provided herein is a means which is effective for botulism diseases and the prevention of the botulism diseases. Specifically provided is a plurality of human anti-botulinum toxin type-A antibodies having different epitopes from one another. Also specifically provided is a composition for neutralizing botulinum toxin type-A, which comprises a combination of two or more of the antibodies and which has a high neutralizing activity.

Composition for neutralizing botulinus toxin type-A, and human anti-botulinus toxin type-A antibody

An antibody library is prepared by selecting a light chain variable region capable of binding to the variable region of heavy chain to reproduce an active conformation and using the same. Because of being capable of maintaining the diversity of the heavy chain variable region at a high ratio in vitro, the antibody library of the present invention is expected as enabling the acquisition of antibodies with various binding activities.

Antibody library

Growing community of inventors

Musashimurayama, Japan

Motohide Takahashi