General Information

  • ID:  hor006624
  • Uniprot ID:  P25687
  • Protein name:  Toxin MIT1
  • Gene name:  NA
  • Organism:  Dendroaspis polylepis polylepis (Black mamba)
  • Family:  AVIT (prokineticin) family
  • Source:  animal
  • Expression:  Expressed by the venom gland.
  • Disease:  NA
  • Comments:  NA
  • Taxonomy:   Dendroaspis polylepis (species), Dendroaspis (genus), Elapinae (subfamily), Elapidae (family), Colubroidea (superfamily), Serpentes (infraorder), Toxicofera , Episquamata , Unidentata , Bifurcata , Squamata (order), Lepidosauria (class), Sauria , Sauropsida , Amniota , Tetrapoda , Dipnotetrapodomorpha , Sarcopterygii (superclass), Euteleostomi , Teleostomi , Gnathostomata , Vertebrata , Craniata (subphylum), Chordata (phylum), Deuterostomia , Bilateria , Eumetazoa , Metazoa (kingdom), Opisthokonta , Eukaryota (superkingdom),cellular organisms
  • GO MF:  GO:0090729 toxin activity
  • GO BP:  GO:0035821 modulation of process of another organism
  • GO CC:  GO:0005576 extracellular region

Sequence Information

  • Sequence:  AVITGACERDLQCGKGTCCAVSLWIKSVRVCTPVGTSGEDCHPASHKIPFSGQRMHHTCPCAPNLACVQTSPKKFKCLSKS
  • Length:  81
  • Propeptide:  AVITGACERDLQCGKGTCCAVSLWIKSVRVCTPVGTSGEDCHPASHKIPFSGQRMHHTCPCAPNLACVQTSPKKFKCLSKS
  • Signal peptide:  NA
  • Modification:  NA
  • Glycosylation:  NA
  • Mutagenesis:  NA

Activity

  • Function:  Potent agonist for both PKR1/PROKR1 and PKR2/PROKR2 (PubMed:12054613). Potently contracts gastrointestinal (GI) smooth muscle (PubMed:10567694).
  • Mechanism:  Negative results: does not inhibit Kv1.1/KCNA1, Kv1.2/KCNA2, Kv1.3/KCNA3, Kv1.4/KCNA4, Kv1.5/KCNA5, Kv2.1/KCNB1, Kv3.4/KCNC4, Kv4.2/KCND2, K2P2.1/KCNK2, Kv11/KCNH, Kv7.1/KCNQ1, Kv7.2/KCNQ2, Kv7.3/KCNQ3, Kir1.1/KCNJ1, Kir2.1/KCNJ2, Kir2.2/KCNJ12, Kir3.1/KCNJ3-Kir3.2/KCNJ6 (GIRK1,2) and Kir3.1/KCNJ3-Kir3.4/KCNJ5 (GIRK1,4).
  • Cross BBB:  NA
  • Target:  NA
  • Target Unid:  NA
  • IC50: NA
  • EC50: NA
  • ED50: NA
  • kd: NA
  • Half life: NA

Structure

  • Disulfide bond:  7-19; 13-31; 18-59; 41-67; 61-77
  • Structure ID:  AF-P25687-F1(AlphaFold_DB_ID)/1IMT(PDB_ID)

  • Structure: (PDB_ID-from https://www.rcsb.org/; AlphaFold_DB_ID-from https://alphafold.ebi.ac.uk/; hordbxxxxxx_AF2.pdb was predicted structure by AlphaFold2; hordbxxxxxx_ESM.pdb was predicted structure by ESMFold)
    •    AF-P25687-F1.pdb1imt.pdbhor006624_AF2.pdbhor006624_ESM.pdb

Physical Information

Mass: 1003122 Formula: C365H594N110O108S11
Absent amino acids: Y Common amino acids: C
pI: 8.59 Basic residues: 14
Polar residues: 31 Hydrophobic residues: 22
Hydrophobicity: -9.75 Boman Index: -10057
Half-Life: 4.4 hour Half-Life Yeast: >20 hour
Half-Life E.Coli: >10 hour Aliphatic Index 62.59
Instability Index: 5113.33 Extinction Coefficient cystines: 6125
Absorbance 280nm: 76.56

Literature

  • PubMed ID:  10567694
  • Title:  MIT(1), a black mamba toxin with a new and highly potent activity on intestinal contraction.
  • PubMed ID:  7461607
  • Title:  Snake venom. The amino acid sequence of protein A from Dendroaspis polylepis polylepis (black mamba) venom.
  • PubMed ID:  12054613
  • Title:  Isolation and identification of EG-VEGF/prokineticins as cognate ligands for two orphan G-protein-coupled receptors.
  • PubMed ID:  9761684
  • Title:  A structural homologue of colipase in black mamba venom revealed by NMR floating disulphide bridge analysis.