title: [Microsequencing, analysis of molecular weight and amino acid composition for pyrimidine 5'-nucleotidase I of human erythrocytes].
abstract: To further explore the mechanism of congenital pyrimidine 5'-nuleotidase I (P5'N-I) deficiency, on the basis of purification of the protein, the molecular weight and amino acid composition were analysed by mass-spectrograph and amino-acid analyzer, microsequencing and bioinformation analysis of P5'N-I were performed after it was hydrolysed by trypsin. The results showed that three fractions were found in the purified P5'N-I and their molecular weights were 26,952.9, 55,476 and 110,938, respectively. The sequence from one of the peptide fragments was I-E-G-P-T-I-R-Q-I-E. The homologous sequence was not found after comparision with the ten-amino-acid sequence in GenBank by blast procedure. Amino acid analysis indicated that P5'N-I was composed of 18 amino acids at least, and 243 amino acid residues. In conclusion, the enzyme might be an allosteric enzyme, there might be homologous dimer or tetramer in physiological status of normal human erythrocyte, the microsequence could be designed as the probe for fishing the genes of interest. The composition of amino acid might be an important information in determination of its protein primary structure.
authors.affiliation: Department of Hematology, Changhai Hospital, The Second Military Medical University, China. paradise806@sohu.com
authors.forename: Zhu-Lin
authors.initials: ZL
authors.lastname: Pan
authors.forename: Jin-Ying
authors.initials: JY
authors.lastname: Li
authors.forename: Bi-He
authors.initials: BH
authors.lastname: Min
authors.forename: Kang
authors.initials: K
authors.lastname: Ying
authors.forename: Hong
authors.initials: H
authors.lastname: Zhou
authors.forename: Xiao-Ping
authors.initials: XP
authors.lastname: Xu
authors.forename: Xian-Min
authors.initials: XM
authors.lastname: Shong
authors.forename: Feng-Lai
authors.initials: FL
authors.lastname: Han
authors.forename: Wei-Ping
authors.initials: WP
authors.lastname: Zhang
authors.forename: Xian
authors.initials: X
authors.lastname: Zhang
mesh_terms: D015720:5'-Nucleotidase / Q000097:blood / Q000737:chemistry* / Q000302:isolation & purification; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis*; D002851:Chromatography, High Pressure Liquid; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000201:enzymology*; D006801:Humans; D013058:Mass Spectrometry; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry; D020539:Sequence Analysis, Protein
chemical_list: D000596:Amino Acids; D010446:Peptide Fragments; D015720:5'-Nucleotidase