TPDB

3D PDB MODEL

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TPDB ID TPDB72737

Activity

Neurotoxin

Activity_category_statistics

Toxicity and safety peptides

Database_Source

NTxPred2

Sequence_Type

standard

Has_Modification No

Description A 37-aa standard natural neurotoxin peptide sequence curated from NTxPred2, with an available 3D structural model.

Sequence

EPCIPKWKSCVNRHGDCCAGLECWKRRKSFEVCVPKV

FASTA

>TPDB72737|Neurotoxin|length=37
EPCIPKWKSCVNRHGDCCAGLECWKRRKSFEVCVPKV

Formula C186H296N56O49S6

Absent Amino Acids QMTY

Common Amino Acids C

Mass 4293.10

PI 8.59

Basic Residues 9

Acidic Residues 4

Hydrophobic Residues 10

Net Charge +4

Boman Index 10.65

Hydrophobicity -0.486

Aliphatic Index 55.14

Half Life

Mammalian: 1 hour Yeast: 30 min E.coli: >10 hour

Extinction Coefficient Cystines 11375

Absorbance 280nm 264.96

Polar Residues 9

number

1

A

3

R

1

N

1

D

6

C

3

E

0

Q

2

G

1

H

1

I

1

L

5

K

0

M

1

F

3

P

2

S

0

T

2

W

0

Y

4

V

Amino Acid Distribution

A: 1 R: 3 N: 1 D: 1 C: 6 E: 3 Q: 0 G: 2 H: 1 I: 1 L: 1 K: 5 M: 0 F: 1 P: 3 S: 2 T: 0 W: 2 Y: 0 V: 4

Length

37

Formula

C186H296N56O49S6

Mass

4293.10

PI

8.59

Net Charge

+4

Boman Index

10.65

Hydrophobicity

-0.486

Evidence 1 Activity

Activity

Detail Source Activity Neurotoxin

Function Text

FUNCTION: This toxin acts on different isoforms of acid-sensing ion channel ASIC1 in a similar manner to psalmotoxin-1 (AC P60514). On ASIC1a homotrimer, it provokes a pH-dependent inhibition (IC(50)=39.7 nM on human and IC(50)=1.3 nM on rat channels), whereas it potentiates ASIC1b homotrimer and ASIC1a-ASIC1b heterotrimer (EC(50)=178.1 nM on human ASIC1b, EC(50)=46.5 nM on rat ASIC1b and EC(50)=17.4 nM on rat ASIC1a-ASIC1b channels). On rat ASIC1a, it acts by inhibiting channel currents by shifting the pH of half-maximal effect (pH(50)) of steady-state desensitization and activation to more alkaline values. {ECO:0000269|PubMed:28327374}.

Target

Target or Channel voltage-gated sodium channel (Nav) proton-gated sodium channel / ASIC

Source & Reference

Database Source NA

Source UniProtKB/Swiss-Prot Tox-Prot

Other

Organism Source Heteroscodra maculata (Togo starburst tarantula) (Togo starburst baboon spider)

Neurotoxin Type Neurotoxin Ion channel impairing toxin Proton-gated sodium channel impairing toxin

Mechanism

This toxin acts on different isoforms of acid-sensing ion channel ASIC1 in a similar manner to psalmotoxin-1 (AC P60514). On ASIC1a homotrimer, it provokes a pH-dependent inhibition (IC(50)=39.7 nM on human and IC(50)=1.3 nM on rat channels), whereas it potentiates ASIC1b homotrimer and ASIC1a-ASIC1b heterotrimer (EC(50)=178.1 nM on human ASIC1b, EC(50)=46.5 nM on rat ASIC1b and EC(50)=17.4 nM on rat ASIC1a-ASIC1b channels).

Protein Name Pi-theraphotoxin-Hm3a (Pi-TRTX-Hm3a)

Venom Taxon Group spider

Protein Family Psalmotoxin-1 family

Protein Existence Evidence at protein level

Keywords Direct protein sequencing Disulfide bond Ion channel impairing toxin Knottin Neurotoxin Proton-gated sodium channel impairing toxin Secreted Toxin

Tissue Specificity TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305|PubMed:28327374}.

Keywords

Direct protein sequencing Disulfide bond Ion channel impairing toxin Knottin Neurotoxin Proton-gated sodium channel impairing toxin Secreted Toxin

Neurotoxin_Type

Neurotoxin Ion channel impairing toxin Proton-gated sodium channel impairing toxin

Protein_Existence

Evidence at protein level

Protein_Family

Psalmotoxin-1 family

Protein_Name

Pi-theraphotoxin-Hm3a (Pi-TRTX-Hm3a)

Tissue_Specificity

TISSUE SPECIFICITY: Expressed by the venom gland. {ECO:0000305|PubMed:28327374}.

Venom_Taxon_Group

spider