The typographical corrections below were made to the article on the date noted. These changes have been incorporated in the article and the details are documented here.

18 August 1999:

In the title of the article, the misspelling "Muring" was corrected to "Murine".

In first sentence of the last paragraph of the Methods, the sentence:

The reduced Insulin B-chain methods was used [13], as....

was corrected to:

The reduced insulin B-chain method was used [13], as....

In paragraph 4 of the Results, the misspelling "800 kD" was corrected to "800 kDa".