TY  - JOUR
A1  - Popova, Antoaneta V.
A1  - Hundertmark, Michaela
A1  - Seckler, Robert
A1  - Hincha, Dirk K.
T1  - Structural transitions in the intrinsically disordered plant dehydration stress protein LEA7 upon drying are modulated by the presence of membranes
JF  - Biochimica et biophysica acta : Biomembranes
N2  - Dehydration stress-related late embryogenesis abundant (LEA) proteins have been found in plants, invertebrates and bacteria. Most LEA proteins are unstructured in solution, but some fold into amphipathic a-helices during drying. The Pfam LEA_4 (Group 3) protein LEA7 from the higher plant Arabidopsis thaliana was predicted to be 87% alpha-helical, while CD spectroscopy showed it to be largely unstructured in solution and only 35% alpha-helical in the dry state. However, the dry protein contained 15% beta-sheets. FTIR spectroscopy revealed the (beta-sheets to be largely due to aggregation. beta-Sheet content was reduced and alpha-helix content increased when LEA7 was dried in the presence of liposomes with secondary structure apparently influenced by lipid composition. Secondary structure was also affected by the presence of membranes in the fully hydrated state. A temperature-induced increase in the flexibility of the dry protein was also only observed in the presence of membranes. Functional interactions of LEA7 with membranes in the dry state were indicated by its influence on the thermotropic phase transitions of the lipids and interactions with the lipid headgroup phosphates.
KW  - Desiccation
KW  - CD spectroscopy
KW  - FTIR spectroscopy
KW  - LEA protein
KW  - Protein-membrane interactions
KW  - Protein secondary structure
Y1  - 2011
U6  - https://doi.org/10.1016/j.bbamem.2011.03.009
SN  - 0005-2736
VL  - 1808
IS  - 7
SP  - 1879
EP  - 1887
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Hundertmark, Michaela
A1  - Popova, Antoaneta V.
A1  - Rausch, Saskia
A1  - Seckler, Robert
A1  - Hincha, Dirk K.
T1  - Influence of drying on the secondary structure of intrinsically disordered and globular proteins
JF  - Biochemical and biophysical research communications
N2  - Circular dichroism (CD) spectroscopy of five Arabidopsis late embryogenesis abundant (LEA) proteins constituting the plant specific families LEA_5 and LEA_6 showed that they are intrinsically disordered in solution and partially fold during drying. Structural predictions were comparable to these results for hydrated LEA_6, but not for LEA_5 proteins. FTIR spectroscopy showed that verbascose, but not sucrose, strongly affected the structure of the dry proteins. The four investigated globular proteins were only mildly affected by drying in the absence, but strongly in the presence of sugars. These data highlight the larger structural flexibility of disordered compared to globular proteins and the impact of sugars on the structure of both disordered and globular proteins during drying.
KW  - Desiccation
KW  - CD spectroscopy
KW  - FTIR spectroscopy
KW  - Intrinsically disordered proteins
KW  - LEA proteins
KW  - Protein secondary structure
Y1  - 2012
U6  - https://doi.org/10.1016/j.bbrc.2011.11.067
SN  - 0006-291X
VL  - 417
IS  - 1
SP  - 122
EP  - 128
PB  - Elsevier
CY  - San Diego
ER  -