The virus-resistant, transgenic commercial papaya Rainbow and SunUp (Carica papaya L.) have been consumed
locally in Hawaii and elsewhere in the mainland United States and Canada since their release to planters in Hawaii in 1998. These
papaya are derived from transgenic papaya line 55-1 and carry the coat protein (CP) gene of papaya ringspot virus (PRSV). The
PRSV CP was evaluated for potential allergenicity, an important component in assessing the safety of food derived from transgenic
plants. The transgene PRSV CP sequence of Rainbow papaya did not exhibit greater than 35% amino acid sequence homology to
known allergens, nor did it have a stretch of eight amino acids found in known allergens which are known common bioinformatic
methods used for assessing similarity to allergen proteins. PRSV CP was also tested for stability in simulated gastric fluid and
simulated intestinal fluid and under various heat treatments. The results showed that PRSV CP was degraded under conditions for
which allergenic proteins relative to nonallergens are purported to be stable. The potential human intake of transgene-derived PRSV
CP was assessed by measuring CP levels in Rainbow and SunUp along with estimating the fruit consumption rates and was
compared to potential intake estimates of PRSV CP from naturally infected nontransgenic papaya. Following accepted allergenicity
assessment criteria, our results show that the transgene-derived PRSV CP does not pose a risk of food allergy.