• The PAH enzyme functions in liver as homo-tetramers to hydroxylate phenylalanine (Phe) into tyrosine and requires the co-factor tetrahydrobiopterin for catalysis. Phenylalanine hydroxylase (PAH) deficiency prevents the conversion of Phe to tyrosine. PAH deficiency results in hyperphenylalaninemia (HPA) and irreversible neurological consequences if left untreated.
• The exons 1-13 of mouse Pah gene that encode the full-length protein were knocked out in B-Pah KO mice..
• Pah protein expression was detected in the liver and kidneys of both female and male wild mice and heterozygous mice. Moreover, Pah protein expression of both female and male wild mice was higher than that of heterozygous mice.
• B-Pah KO mice provide a powerful preclinical model for further development of gene and cell biologics to treat phenylketonuria(PKU).
• Application: For example, this product is to add to the experimental tools available for PKU scientists and to advance PKU research.

Gene targeting strategy for B-Pah KO mice. The exons 1-13 of mouse Pah gene that encode the full-length protein were knocked out in B-Pah KO mice.

Western blot analysis of Pah protein expression in homozygous B-Pah KO mice. Various tissue lysates were collected from wild-type C57BL/6 mice (+/+) and homozygous B-Pah KO mice (-/-), and then analyzed by western blot with anti-Pah antibody(abcam, ab178430). 40 μg total proteins were loaded for western blotting analysis. Pah protein expression was detected in the liver and kidneys of wild mice but not in homozygous B-Pah KO mice.

Strain specific analysis of PAH mRNA expression in wild-type C57BL/6 mice and B-Pah KO mice by RT-PCR. Liver RNA were isolated from wild-type C57BL/6 mice (+/+) and homozygous B-Pah KO mice (-/-), then cDNA libraries were synthesized by reverse transcription, followed by PCR with mouse Pah primers. Mouse Pah mRNA was exclusively detectable in wild-type mice but not in homozygous B-Pah KO mice.

Hair coat color and body weight in homozygous B-Pah KO mice. (A) When compared to wild-type C57BL/6 mice (+/+, male, 7-week-old), homozygous B-Pah KO mice (-/-, male, 7-week-old) exhibit gray fur. (B) For body weight, wild-type control and homozygous B-Pah KO mice (n=4, male, 4-week-old; n=6, female, 4-week-old) were analyzed, which revealed that the body weight of homozygous B-Pah KO mice was significantly lower than that of wild-type mice. Values are expressed as mean ± SEM. Significance was determined by unpaired t test.  *P < 0.05, **P < 0.01, ***P < 0.001, ****P < 0.0001.