J. Horwitz et al., MUTATION OF ALPHA-B-CRYSTALLIN - EFFECTS ON CHAPERONE-LIKE ACTIVITY, International journal of biological macromolecules, 22(3-4), 1998, pp. 263-269
A recent paper by Plater et al. [20], showed that the mutation of a si
ngle phenylalanine residue F27R in mouse alpha B completely abolished
the chaperone-like property of alpha-crystallin when assayed with insu
lin at 25 degrees C or with gamma-crystallin at 66 degrees C. We have
produced the same mutation as well as some additional mutations in hum
an alpha B-crystallin. Our data suggest that the F27R mutation effecte
d the thermal stability of alpha B-crystallin making it unstable at te
mperatures greater than or equal to 60 degrees C. In agreement with th
e published work, at these temperatures the F27R human recombinant alp
ha B-crystallin does not protect the target protein from aggregation.
When assayed with insulin or alpha-lactalbumin at 25 or 37 degrees C,
however, there were no differences in the protective abilities between
the native alpha B-crystallin or the F27R mutated human alpha B-cryst
allin. Several other multiple mutations involving proline residues wer
e also produced. These mutations did not effect the chaperone-like pro
perties of human alpha B-crystallin, but some of them did effect the n
ative molecular weight size as judged by gel filtration chromatography
. (C) 1998 Elsevier Science B.V. All rights reserved.