The invention relates to a pharmaceutical composition containing a PLP-dependent enzyme and optionally its cofactor, pyridoxal phosphate (PLP), and/or a phosphate or non-phosphate precursor of PLP, its use as a drug, its production method and a therapeutic treatment method related to it. The pharmaceutical composition comprises erythrocytes and a pharmaceutically acceptable vehicle, the erythrocytes encapsulating the PLP-dependent enzyme. The PLP-dependent enzyme may be methioninase, tyrosine phenol-lyase, tyrosine aminotransferase or cystathionine beta-synthase.

Provided is a use of an agent for regulating an amino acid level in preparing a drug for treating Alzheimer's disease in a subject.

The invention relates to a pharmaceutical composition containing a PLP-dependent enzyme and optionally its cofactor, pyridoxal phosphate (PLP), and/or a phosphate or non-phosphate precursor of PLP, its use as a drug, its production method and a therapeutic treatment method related to it. The pharmaceutical composition comprises erythrocytes and a pharmaceutically acceptable vehicle, the erythrocytes encapsulating the PLP-dependent enzyme. The PLP-dependent enzyme may be methioninase, tyrosine phenol-lyase, tyrosine aminotransferase or cystathionine beta-synthase.

The invention relates to a pharmaceutical composition containing a PLP-dependent enzyme and optionally its cofactor, pyridoxal phosphate (PLP), and/or a phosphate or non-phosphate precursor of PLP, its use as a drug, its production method and a therapeutic treatment method related to it. The pharmaceutical composition comprises erythrocytes and a pharmaceutically acceptable vehicle, the erythrocytes encapsulating the PLP-dependent enzyme. The PLP-dependent enzyme may be methioninase, tyrosine phenol-lyase, tyrosine aminotransferase or cystathionine beta-synthase.

An engineered microorganism, which comprises one or more of a gene encoding an aromatic amino acid transaminase, a gene encoding phenylalanine dehydrogenase, a gene encoding phenylpyruvate decarboxylase, a gene encoding an aldehyde reductase, a gene encoding glutamate dehydrogenase, and a gene encoding a phenylalanine transport protein, or a functional equivalent thereof. The present invention also relates to a composition comprising the engineered microorganism; a method for using the engineered microorganism or the composition to alleviate and/or treat diseases and/or conditions associated with hyperphenylalaninemia; and use of the engineered microorganism or the composition in the preparation of medicaments or health products for treating diseases and/or conditions associated with hyperphenylalaninemia.