A theoretical model of a plant antifreeze protein from Lolium perenne.
Biophys J
; 81(6): 3560-5, 2001 Dec.
Article
en En
| MEDLINE
| ID: mdl-11721016
Antifreeze proteins (AFPs), found in certain organisms enduring freezing environments, have the ability to inhibit damaging ice crystal growth. Recently, the repetitive primary sequence of the AFP of perennial ryegrass, Lolium perenne, was reported. This macromolecular antifreeze has high ice recrystallization inhibition activity but relatively low thermal hysteresis activity. We present here a theoretical three-dimensional model of this 118-residue plant protein based on a beta-roll domain with eight loops of 14-15 amino acids. The fold is supported by a conserved valine hydrophobic core and internal asparagine ladders at either end of the roll. Our model, which is the first proposed for a plant AFP, displays two putative, opposite-facing, ice-binding sites with surface complementarity to the prism face of ice. The juxtaposition of the two imperfect ice-binding surfaces suggests an explanation for the protein's inferior thermal hysteresis but superior ice recrystallization inhibition activity and activity when compared with fish and insect AFPs.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Plantas
/
Lolium
/
Proteínas Anticongelantes
Límite:
Animals
Idioma:
En
Revista:
Biophys J
Año:
2001
Tipo del documento:
Article
País de afiliación:
Canadá
Pais de publicación:
Estados Unidos