INTRODUCTION: The primary structure of human chromogranin B (CgB) contains 15 pairs of basic amino acids, which are potential cleavage sites for specific endogenous proteases, but also other sites in the molecule can be subjected to cleavage. Several CgB-related peptides have been identified in tissue extracts. MATERIALS AND METHODS: Peptides homologous to defined parts of the human CgB molecule were selected and synthesized. Antibodies were raised and 13 specific radioimmunoassays were developed. Plasma samples from 19 patients with neuroendocrine tumors were collected and measured in all assays. RESULTS: All region-specific assays measured circulating levels of CgB-related peptides. Only five of the assays measured high concentrations of circulating CgB and two of them correlated with that of intact chromogranin A (CgA). CONCLUSION: The assays presented allow measurements of defined regions of CgB and will thus become important tools for further studies of the processing of CgB. One of the assays merit further investigations as a new marker for neuroendocrine tumors.
INTRODUCTION: The primary structure of humanchromogranin B (CgB) contains 15 pairs of basic amino acids, which are potential cleavage sites for specific endogenous proteases, but also other sites in the molecule can be subjected to cleavage. Several CgB-related peptides have been identified in tissue extracts. MATERIALS AND METHODS: Peptides homologous to defined parts of the humanCgB molecule were selected and synthesized. Antibodies were raised and 13 specific radioimmunoassays were developed. Plasma samples from 19 patients with neuroendocrine tumors were collected and measured in all assays. RESULTS: All region-specific assays measured circulating levels of CgB-related peptides. Only five of the assays measured high concentrations of circulating CgB and two of them correlated with that of intact chromogranin A (CgA). CONCLUSION: The assays presented allow measurements of defined regions of CgB and will thus become important tools for further studies of the processing of CgB. One of the assays merit further investigations as a new marker for neuroendocrine tumors.
Authors: J McKee Alderman; Kevin Flurkey; Natasha L Brooks; Sneha B Naik; Jonathan M Gutierrez; Urmila Srinivas; Kristen B Ziara; Linhong Jing; Gunnar Boysen; Rod Bronson; Simon Klebanov; Xian Chen; James A Swenberg; Mats Stridsberg; Carol E Parker; David E Harrison; Terry P Combs Journal: Exp Gerontol Date: 2008-06-07 Impact factor: 4.032
Authors: Joel Jakobsson; Mats Stridsberg; Henrik Zetterberg; Kaj Blennow; Carl-Johan Ekman; Anette G M Johansson; Carl Sellgren; Mikael Landén Journal: J Psychiatry Neurosci Date: 2013-07 Impact factor: 6.186