Multiple email addresses - any alternative to ask everyone to sign all my keys?

[Philipp Klaus Krause]

I'm currently using 4 email addresses - 1 for private mail, 1 for a
small business, and 2 for university. Currently I have three keys - one
for the private mail, one for the business, and one for unversity. Each
of the keys has been signed with all keys.

Of course it is annoying to have to ask everyone to sign three keys -
after all they are all my keys, and the people I ask to sign my key all
get to see the same passport. Is there a better alternative?

I do not consider my university computer safe enough to trust it with
the private key for my private mail. I.e. I do not want someone who
breaks into the university office and installs a keylogger to be able to
read encrypted mail sent to my private account.

Philipp