RT Book, Section A1 Tannous, Zeina A1 Avram, Mathew M. A1 Tsao, Sandy A1 Avram, Marc R. SR Print(0) ID 1175821444 T1 Botulinum Toxin T2 Color Atlas of Cosmetic Dermatology, 2e YR 2011 FD 2011 PB The McGraw-Hill Companies, Inc. PP New York, NY SN 9780071635035 LK dermatology.mhmedical.com/content.aspx?aid=1175821444 RD 2024/04/24 AB Botulinum toxin is a protein produced by the bacterium Clostridium botulinum. Seven serotypes exist, designated as A, B, C1, D, E, F, and G. Each one of them is a protease with a light chain linked to a heavy chain by a disulfide bond.