Special dietary proteins

Abstract

The invention discloses a group of special dietary proteins, and belongs to the field of phenylketonuria dietetic therapy. The proteins are prepared by the following steps: artificially designing andoptimizing proteins with high natural expression quantity, reducing the phenylalanine content, and increasing the LNAA content at the same time. Through genetic engineering bacterium transformation and production process optimization, the obtained protein powder is high in purity and good in taste, and the content of phenylalanine in blood of a phenylketonuria model mouse can be effectively controlled when the phenylketonuria model mouse is fed with the protein powder. Therefore, the protein powder is suitable for dietary therapy of phenylketonuria. The production cost of the recombinant phenylalanine-free / low-phenylalanine protein powder prepared by the invention can be reduced to the price of a common protein product, and the protein powder has huge practical application value and wide market prospect.

Description

technical field [0001] The invention belongs to the field of diet therapy for phenylketonuria, and in particular relates to a recombinant protein with no / low phenylalanine content suitable for patients with hyperphenylalaninemia or phenylketonuria. Background technique [0002] Phenylketonuria (PKU) is a rare genetic disease of amino acid metabolism. The incidence rate in Chinese newborns is about 1:11800, and the total number of PKU patients in China is about 120,000. PKU is an autosomal recessive inheritance, which is due to the absence of key enzymes (PAH) or cofactors (BH4) in the phenylalanine metabolic pathway, so that phenylalanine cannot be converted into tyrosine, resulting in phenylalanine and tyrosine. Its keto acid accumulates in the brain and plasma, also known as hyperphenylalaninemia (HPA), and the phenylalanine in the body is mainly excreted in the urine. The typical symptoms begin to appear when the patient is 3-4 months old, and the symptoms are obvious wh...

AI Technical Summary

Problems solved by technology

There are many disadvantages in the traditional phenylalanine-restricted diet therapy: (1) Since the protein of most foods contains phenylalanine, the food that can be selected is very limited, and you can only choose protein-free or very low-protein foods. (2) Using amino acid compound powder as a substitute for dietary protein, because many amino acids have a strong bitter taste and special unpleasant smell, resulting in amino acid compound powder The taste of the food is poor, and the patient's treatment compliance is poor; in addition, due to oral administration of a large amount of free amino acids, the osmotic pressure of the intestinal tract is disturbed, causing intestinal discomfort and intestinal metabolic disorders; thirdly, the food form that amino acid powder can be made into is very limited , long-term use leads to a decline in the quality of life of patients

(3) Continuous neurological and psychological problems due to poor quality of life; (4) Long-term dietary restrictions or single choices lead to nutritional deficiencies; (5) The cost of special foods and nutrients is relatively high, and the family burden is heavy

LN AA supplements also face the disadvantages of oral amino acids, such as heavy bitter taste, poor taste, intestinal discomfort and intestinal dysfunction, etc.

[0013] Common high-quality food proteins, such as whey protein, egg protein, soybean protein, etc., have relatively high phenylalanine content (about 3.1-5.35%) [Christopher J. Rasmussen, Nutritional Supplements in Sports and Exercise, (2008); Maria Minnaar, USDA, (1994)], not suitable for consumption by patients with phenylketonuria

In addition, the ratio of LNAA to phenylalanine of these proteins is low (about 5.89-11.06), which cannot inhibit the entry of phenylalanine into the brain

At present, it is the only natural low-phenylalanine food protein suitable for patients with phenylketonuria --- glycomacropeptide. Use, affect the taste experience

[0014] At present, there is no protein that can meet all the amino acid requirements of patients with phenylketonuria and can be used as the only protein food source for patients with phenylketonuria

At the same time, there is no dietary protein that meets the low phenylalanine content and contains a high proportion of LNAA amino acids

Images