title: Digestion of Nucleic Acids Starts in the Stomach.
abstract: The ingestion of nucleic acids (NAs) as a nutritional supplement or in genetically modified food has attracted the attention of researchers in recent years. Discussions over the fate of NAs led us to study their digestion in the stomach. Interestingly, we found that NAs are digested efficiently by human gastric juice. By performing digests with commercial, recombinant and mutant pepsin, a protein-specific enzyme, we learned that the digestion of NAs could be attributed to pepsin rather than to the acidity of the stomach. Further study showed that pepsin cleaved NAs in a moderately site-specific manner to yield 3'-phosphorylated fragments and the active site to digest NAs is probably the same as that used to digest protein. Our results rectify the misunderstandings that the digestion of NAs in the gastric tract begins in the intestine and that pepsin can only digest protein, shedding new light on NA metabolism and pepsin enzymology.
authors.affiliation: College of food science and engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Liu
authors.affiliation: College of food science and engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Yanfang
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: College of food science and engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Ping
authors.initials: P
authors.lastname: Dong
authors.affiliation: College of food science and engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Ran
authors.initials: R
authors.lastname: An
authors.affiliation: College of food science and engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Changhu
authors.initials: C
authors.lastname: Xue
authors.affiliation: Department of Biochemistry and Molecular Biology, Qingdao University Medical College, Qingdao 266003, China.
authors.forename: Yinlin
authors.initials: Y
authors.lastname: Ge
authors.affiliation: Department of Biochemistry and Molecular Biology, Qingdao University Medical College, Qingdao 266003, China.
authors.forename: Liangzhou
authors.initials: L
authors.lastname: Wei
authors.affiliation: College of food science and engineering, Ocean University of China, Qingdao 266003, China.
authors.forename: Xingguo
authors.initials: X
authors.lastname: Liang
mesh_terms: D001483:Base Sequence; D004247:DNA / Q000737:chemistry / Q000378:metabolism; D004279:DNA, Viral / Q000235:genetics / Q000378:metabolism; D019587:Dietary Supplements; D005750:Gastric Juice / Q000378:metabolism; D005753:Gastric Mucosa / Q000378:metabolism*; D006801:Humans; D006868:Hydrolysis; D008969:Molecular Sequence Data; D009696:Nucleic Acids / Q000378:metabolism*; D010434:Pepsin A / Q000037:antagonists & inhibitors / Q000378:metabolism; D010436:Pepstatins / Q000378:metabolism / Q000494:pharmacology
chemical_list: D004279:DNA, Viral; D009696:Nucleic Acids; D010436:Pepstatins; D004247:DNA; D010434:Pepsin A; C031375:pepstatin