In:
FEBS Letters, Wiley, Vol. 429, No. 1 ( 1998-06-05), p. 78-82
Abstract:
Tyrosine phosphorylation of botulinum neurotoxins augments their proteolytic activity and thermal stability, suggesting a substantial modification of the global protein conformation. We used Fourier‐transform infrared (FTIR) spectroscopy to study changes of secondary structure and thermostability of tyrosine phosphorylated botulinum neurotoxins A (BoNT A) and E (BoNT E). Changes in the conformationally‐sensitive amide I band upon phosphorylation indicated an increase of the α‐helical content with a concomitant decrease of less ordered structures such as turns and random coils, and without changes in β‐sheet content. These changes in secondary structure were accompanied by an increase in the residual amide II absorbance band remaining upon H‐D exchange, consistent with a tighter packing of the phosphorylated proteins. FTIR and differential scanning calorimetry (DSC) analyses of the denaturation process show that phosphorylated neurotoxins denature at temperatures higher than those required by non‐phosphorylated species. These findings indicate that tyrosine phosphorylation induced a transition to higher order and that the more compact structure presumably imparts to the phosphorylated neurotoxins the higher catalytic activity and thermostability.
Type of Medium:
Online Resource
ISSN:
0014-5793
,
1873-3468
DOI:
10.1016/S0014-5793(98)00571-7
Language:
English
Publisher:
Wiley
Publication Date:
1998
detail.hit.zdb_id:
1460391-3
SSG:
12
Permalink