title: Amino-terminal amino acid sequence of murine colony-stimulating factor 1.
abstract: We report the amino acid composition, the NH2-terminal sequence, and the tryptic map by HPLC for murine L-cell colony-stimulating factor 1 (CSF-1). CSF-1 purified by affinity chromatography was S-carboxymethylated under denaturing conditions and subjected to sequence microanalysis. CSF-1 contains four or five cysteine residues per subunit and approximately 30-40% carbohydrate by weight. Three contiguous cysteine residues were located in the NH2-terminal sequence. An additional two cysteine residues were located on the tryptic map. Previous studies as well as immunoblotting studies reported here suggest that sulfhydryl bridging plays a major role in maintaining the conformation of the protein. Carbohydrate was located on two tryptic fragments. The findings of a single NH2-terminal sequence in high yield and a relatively simple tryptic map (15 major peptides) suggest that CSF-1 contains two identical subunits. The NH2-terminal sequence of CSF-1 has only limited homology to insulin or insulin-like hormones but no homology with granulocyte/macrophage-CSF or interleukin 3.
mesh_terms: D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002846:Chromatography, Affinity; D002851:Chromatography, High Pressure Liquid; D003115:Colony-Stimulating Factors / Q000032:analysis*; D006133:Growth Substances / Q000032:analysis*; D007328:Insulin / Q000032:analysis; D007377:Interleukin-3; D008222:Lymphokines / Q000032:analysis; D051379:Mice; D009930:Organic Chemicals; D011489:Protein Denaturation; D014357:Trypsin / Q000378:metabolism
chemical_list: D000596:Amino Acids; D002241:Carbohydrates; D003115:Colony-Stimulating Factors; D006133:Growth Substances; D007328:Insulin; D007377:Interleukin-3; D008222:Lymphokines; D009930:Organic Chemicals; C042320:colony promoting activity; D014357:Trypsin