Identification and Characterization of an Isoform Antifreeze Protein from the Antarctic Marine Diatom, Chaetoceros neogracile and Suggestion of the Core Region.
Mar Drugs
; 15(10)2017 Oct 18.
Article
en En
| MEDLINE
| ID: mdl-29057803
ABSTRACT
Antifreeze proteins (AFPs) protecting the cells against freezing are produced in response to extremely low temperatures in diverse psychrophilic organisms, and they are encoded by multiple gene families. The AFP of Antarctic marine diatom Chaetoceros neogracile is reported in our previous research, but like other microalgae, was considered to probably have additional genes coding AFPs. In this paper, we reported the cloning and characterization of additional AFP gene from C. neogracile (Cn-isoAFP). Cn-isoAFP protein is 74.6% identical to the previously reported Cn-AFP. The promoter sequence of Cn-isoAFP contains environmental stress responsive elements for cold, thermal, and high light conditions. Cn-isoAFP transcription levels increased dramatically when cells were exposed to freezing (-20 °C), thermal (10 °C), or high light (600 µmol photon m-2 s-1) stresses. The thermal hysteresis (TH) activity of recombinant Cn-isoAFP was 0.8 °C at a protein concentration of 5 mg/mL. Results from homology modeling and TH activity analysis of site-directed mutant proteins elucidated AFP mechanism to be a result of flatness of B-face maintained via hydrophobic interactions.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Diatomeas
/
Isoformas de Proteínas
/
Proteínas Anticongelantes
/
Congelación
Tipo de estudio:
Diagnostic_studies
Idioma:
En
Revista:
Mar Drugs
Asunto de la revista:
BIOLOGIA
/
FARMACOLOGIA
Año:
2017
Tipo del documento:
Article