w-Grammotoxin SIA (Grammostola spatulata)
- 貨號 Cat. No.
- G-450
- 規格 Size
- 5 μg 5x5 μg
Description
w-Grammotoxin SIA (Grammostola spatulata)
A Novel Blocker to Cav2.1 (P-type) and Cav2.2 (N-type) Voltage-Gated Ca2+ Channels
| Product#: | G-450 |
| Sizes: |
| 5 mg |
| 5 x 5 mg |
| M.W.: | 4113 daltons |
| Sequence: | DCVRF WGKCS QTSDC CPHLA CKSKW PRNIC VWDGS V |
| Purity: | >98% by HPLC |
| Bioassay: |
The bioactivity of w -Grammotoxin SIA was tested on cloned CaV2.2 channels expressed in Xenopus oocytes, where a concentration of 500 nM caused approximately 60% inhibition (see Figure below). |
 |
w -Grammotoxin SIA effect on cloned N-type (CaV2.2/ a2d1/b2a) channels expressed in Xenopus oocytes using two electrode voltage clamp. The time course on the left shows current amplitude in response to 100 ms test pulse to 0 mV delivered every 10 seconds, before, during (bar) and after application of 500 nM of w -Grammotoxin SIA. The box denoting +100 mV shows the period in which similar pulses to +100 mV were delivered in order to partially relieve the inhibition. The current traces on the right were taken at the indicated positions a and b. |
| References: |
1. | Lampe R.A. et al. (1993) Mol. Pharmacol. 44, 451. |
2. | Piser T.M. et al. (1995) Mol. Pharmacol. 48, 131. |
3. | McDonough, S.I. et al. (1997) Mol. Pharmacol. 52, 1095. |
w-Grammotoxin SIA is a native toxin isolated from venom of the South American Tarantula spider Grammostola spatulata. w-Grammotoxin SIA potently inhibits both Cav2.1 (P-type) and Cav2.2 (N-type) Ca2+ channels by altering the voltage-dependence of channel gating. w-Grammotoxin SIA caused a concentration-dependent and virtually complete inhibition of K+-evoked influx of 45Ca2+ into either rat or chick brain synaptosomes.1 w-Grammotoxin SIA at 1 mM, a maximally effective concentration, blocked 52% of IBa in cultured rat hippocampal neurons.2 A concentration of >50 nM toxin completely inhibited Ca2+ currents in Purkinje neurons (predominantly, P-type channels) and in sympathetic neurons (predominantly, N-type channels).3