DB<6> $p = 'ALTAMCMNVWEITYHKGSDVNRRASFAQPPPQPPPPLLAIKPASDASD';

  DB<7> @b = split /[KR](?!P)/, $p;

  DB<8> x \@b;
0  ARRAY(0x6004f0f88)
   0  'ALTAMCMNVWEITYH'
   1  'GSDVN'
   2  ''
   3  'ASFAQPPPQPPPPLLAIKPASDASD'