Ability of human SNAP-23 to generate high molecular weight SDS-resistant ternary SNARE complexes is influenced by C-terminal coil content

• Published in: Biochemistry and biophysics reports 2021-12, Vol.28, p.101150-101150, Article 101150
• Main Authors: Vaidyanathan, Vadakkanchery V., Binz, Thomas
• Format: Article
• Language: English
• Subjects: Botulinum neurotoxin cleavage; C-terminal coiled-coil content; SDS-Resistant ternary SNARE complexes; Short Communication; SNAP-25 and SNAP-23 proteins
• ISSN: 2405-5808; 2405-5808
• DOI: 10.1016/j.bbrep.2021.101150

Using in vitro protein complex formation assay, ability of SNAP-25 isoforms to generate SDS-resistant ternary SNARE complexes with Syntaxin-1 and VAMP-2 was investigated. Major SNAP-25 family proteins were found to generate heat-resistant ternary complexes with varying efficiency. Compared to human SNAP-25, its non-neuronal counterparts SNAP-23 and SNAP-29 formed lower amounts of ternary complexes. Changing Pro182 in human SNAP-23 to Arg182 (SNAP-23 P182R) improved its ability to bind partners and form complexes. In silico analysis of C-terminal helical content in various SNAP-25 family members showed that except human SNAP-23, all others displayed secondary α-helical conformation. We also report that human SNAP-29 is resistant to the proteolytic action of botulinum neurotoxin A even when applied at large concentration. •Human SNAP-23 forms reduced amounts of ternary SNARE complexes than human SNAP-25.•SNAP-25 family proteins show varying levels of secondary structure at the C-terminus.•C-terminal coil content influences neurotoxin sensitivity and ability to form stable ternary SNARE complexes.