Chaperone activities of bovine and camel beta-caseins: Importance of their surface hydrophobicity in protection against alcohol dehydrogenase aggregation.
Beta-casein (beta-CN) showing properties of intrinsically unstructured proteins (IUP) displays many similarities with molecular chaperones and shows anti-aggregation activity in vitro. Chaperone activities of bovine and camel beta-CN were studied using alcohol dehydrogenase (ADH) as a substrate. To obtain an adequate relevant information about the chaperone capacities of studied caseins, three different physical parameters including chaperone constant (k(c), microM(-1)), thermal aggregation constant (k(T), degrees C(-1)) and aggregation rate constant (k(t), min(-1)) were measured. Bovine beta-CN displays greater chaperone activity than camel beta-CN. Fluorescence studies of 8-anilino-1-naphthalenesulfonic acid (ANS) binding demonstrated that bovine beta-CN is doted with larger effective hydrophobic surfaces at all studied temperatures than camel beta-CN. Greater relative hydrophobicity of bovine beta-CN than camel beta-CN may be a factor responsible for stronger interactions of bovine beta-CN with the aggregation-prone pre denatured molecular species of the substrate ADH, which resulted in greater chaperone activity of bovine beta-CN.
Barzegar
Abolfazl
A
Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
Yousefi
Reza
R
Sharifzadeh
Ahmad
A
Dalgalarrondo
Michèle
M
Chobert
Jean-Marc
JM
Ganjali
Mohammad Reza
MR
Norouzi
Parviz
P
Ehsani
Mohammad Reza
MR
Niasari-Naslaji
Amir
A
Saboury
Ali Akbar
AA
Haertlé
Thomas
T
Moosavi-Movahedi
Ali Akbar
AA
D000426:Alcohol Dehydrogenase / Q000737:chemistry*; D000595:Amino Acid Sequence; D000817:Anilino Naphthalenesulfonates / Q000737:chemistry; D000818:Animals; D002162:Camelus; D002364:Caseins / Q000737:chemistry*; D002417:Cattle; D004305:Dose-Response Relationship, Drug; D006736:Horses; D008099:Liver / Q000378:metabolism; D008823:Micelles; D018832:Molecular Chaperones / Q000737:chemistry*; D008969:Molecular Sequence Data; D017386:Sequence Homology, Amino Acid; D013696:Temperature
C515594:8-anilino-1-naphthalenesulfonic acid; D000817:Anilino Naphthalenesulfonates; D002364:Caseins; D008823:Micelles; D018832:Molecular Chaperones; D000426:Alcohol Dehydrogenase