Connective tissue activation. XXXII. Structural and biologic characteristics of mesenchymal cell-derived connective tissue activating peptide-V.
Connective tissue activating peptide-V (CTAP-V) is a single-chain, mesenchymal cell-derived anionic protein with large and small molecular forms (Mr of 28,000 and 16,000, respectively), as defined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The proteins have similar specific activities with respect to stimulation of hyaluronic acid and DNA formation in human synovial fibroblast cultures. S-carboxymethylation or removal of sialic acid residues did not modify CTAP-V biologic activity. Rabbit antibodies raised separately against each of the purified CTAP-V proteins reacted, on immunodiffusion and on Western blot, with each antigen and neutralized mitogenic activity. The amino-terminal amino acid sequence of the CTAP-V proteins, determined by 2 laboratories, confirmed their structural similarities. The amino-terminal sequence through 37 residues was demonstrated for the smaller protein. The first 10 residues of CTAP-V (28 kd) were identical to the N-terminal decapeptide of CTAP-V (16 kd). The C-terminal sequence, determined by carboxypeptidase Y digestion, was the same for both CTAP-V molecular species. The 2 CTAP-V peptides had similar amino acid compositions, whether residues were expressed as a percent of the total or were normalized to mannose. Reduction of native CTAP-V protein released sulfhydryl groups in a protein:disulfide ratio of 1:2; this suggests that CTAP-V contains 2 intramolecular disulfide bonds. Clearly, CTAP-V is a glycoprotein. The carbohydrate content of CTAP-V (16 kd) and CTAP-V (28 kd) is 27% and 25%, respectively. CTAP-V may have significance in relation to autocrine mechanisms for growth regulation of connective tissue cells and other cell types.
D000118:Acetylglucosaminidase; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D002241:Carbohydrates / Q000032:analysis; D002478:Cells, Cultured; D055598:Chemical Phenomena; D002621:Chemistry; D003238:Connective Tissue / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis; D004591:Electrophoresis, Polyacrylamide Gel; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000096:biosynthesis; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis* / Q000494:pharmacology
D000596:Amino Acids; D002241:Carbohydrates; D010455:Peptides; C009862:connective tissue-activating peptide; D006820:Hyaluronic Acid; D004247:DNA; D000118:Acetylglucosaminidase; D017038:Mannosyl-Glycoprotein Endo-beta-N-Acetylglucosaminidase