文章基本信息

标题：Delayed Removal of N-Terminal Methionine from Nascent Globin Chains in Sickle-Cell Anemia Reticulocytes
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作者：Haruo Suzuki ; Harvey A. Itano
期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1973
卷号：70
期号：7
页码：2059-2063
DOI：10.1073/pnas.70.7.2059
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：Synthetic [α]T1 and {beta}T1, the N-terminal tryptic peptides of [α]-chain and {beta}-chain of hemoglobin, and Met[α]T1 and Met{beta}T1, peptides in which N-terminal methionyl residues are peptide-bonded to [α]T1 and {beta}T1, were prepared by the solid-state method of Merrifield. These synthetic peptides were used to establish conditions for chromatographic purification and analysis. When tryptic digests of nascent globin chains from rabbit and sickle-cell anemia reticulocytes incubated with 35S- and 3H-labeled amino acids were analyzed, radioactivity not present in tryptic digests of labeled hemoglobin appeared at the elution positions of Met[α]T1 and Met{beta}T1. The fraction of nascent chains with N-terminal methionine was higher in sickle-cell anemia reticulocytes than in rabbit reticulocytes. If rate of peptide-chain elongation in polysomes is uniform, nascent human chains must attain a greater length before removal of the initial methionyl residue. Length of nascent chain at time of removal was calculated from two independent sets of data, one obtained from [35S]methionine incorporation into Met[α]T1, Met{beta}T1, [α]T5, and {beta}T5, and the other obtained from [3H]lysine and [3H]valine incorporation into Met{beta}T1 and {beta}T1.
关键词：hemoglobin synthesis ; initiation ; peptide synthesis ; peptide chromatography ; polypeptide folding