Q9FPK2 http://ca.expasy.org/cgi-bin/niceprot.pl?Q9FPK2

Q9FPK3 http://ca.expasy.org/cgi-bin/niceprot.pl?Q9FPK3

Q9FPK4 http://ca.expasy.org/cgi-bin/niceprot.pl?Q9FPK4

Q9SWR4 http://ca.expasy.org/cgi-bin/niceprot.pl?Q9SWR4

Cor a 1
http://ca.expasy.org/cgi-bin/niceprot.pl?Q08407 and
http://us.expasy.org/cgi-bin/niceprot.pl?Q39454 are found in pollen.

Cor a 1.04 is thermolabile and rapidly denatures after heating (Wensing et al 2001 [234]; Vieths et al 1998 [230]; Schocker et al 2000 [182]). Although Pastorello et al. (2002) [671] reported that roasted nuts did not inhibit IgE binding to the 18 kDa allergen (EAST inhibition), Skamstrup Hansen et al. (2003) [665] reported that roasting of the nuts at 140°C for 40 min did not completely remove IgE binding but reduced it by a factor of 100.

The protein is also broken down readily by proteases, with pepsin treatment of hazelnut extract resulting in an almost complete loss of Cor a 1 (Vieths et al. 1999 [1118]; Akkerdaas et al 2000 [4]).

Cor a 1.04 can be affinity purified from hazelnut PVPP extract with Bet v 1 crossreactive mAb 5H8 (Akkerdaas et al. unpublished data).

Recombinant Cor a 1.0401 has been expreseed in E. coli as a 73 kDa intein fusion protein. This was loaded onto a chitin column, washed and treated with 30 mM DTT at 15°C overnight for the cleavage reaction and the 18 kDa Cor a 1.0401 eluted. Yields were 0.6 to 1.3 mg/l of bacterial culture (Lüttkopf et al. 2002 [663]).

Q39454 (Cor a 1) and Q9FPK2 (Cor a 1.0402) are 71% identical and the other Cor a 1.04 sequences are 70% identical to Q39454. The level of identity between Cor a 1.0401 (or the very similar sequences Q9FPK2, Q9FPK3, Q9FPK4, Q9SWR4) and the pollen sequence originally called Cor a 1 (MPAA_CORAV or Q08407) is only 53%. MPAA_CORAV and Q39454 are 64% identical.

Lüttkopf et al. (2002) [663] report that the N-terminal sequence of natural Cor a 1.04 from immunoblots was GVFEYEDEATSVIPP which is identical to the recombinant protein except at position 4 (E4C or E4S).