Bredkjaer H E, Rønnov-Jessen D, Fahrenkrug L, Ekblad E, Fahrenkrug J
Department of Clinical Chemistry, Bispebjerg Hospital, Copenhagen, Denmark.
Regul Pept. 1991 Apr 25;33(2):145-64. doi: 10.1016/0167-0115(91)90209-y.
In order to study biosynthetic processing of the precursor for vasoactive intestinal peptide (preproVIP) in the human gut we have developed antisera against the five functional domains of the precursor molecule: preproVIP 22-79, peptide histidine methionine (PHM), preproVIP 111-122, VIP and preproVIP 156-170. The antisera were used to quantify and characterize VIP-precursor peptides by radioimmunoassay (RIA) together with high-pressure liquid Uchromatography (HPLC) and to examine their cellular localization and colocalization by immunocytochemistry. All five peptides were expressed but not in equimolar amounts as expected from the amino acid sequence of the precursor. However, the ratios between them were fairly constant throughout the gastrointestinal tract. The only exceptions were the lower concentrations of PHM and preproVIP 111-122 in the gastric antrum which could be explained by the presence of PHV (the C-terminally extended form of PHM which includes preproVIP 111-122) in large concentrations in this region. It was also found that the C-terminal lysine residue of preproVIP is not removed during processing. Immunocytochemically all preproVIP-derived peptides were shown in neuronal elements. They had a similar distribution throughout the gut suggesting coexistence, a finding which was supported by doublestaining. The findings indicate that differences in the posttranslational processing of preproVIP exist in subpopulations of neurons in the human gut.
为了研究人肠道中血管活性肠肽前体（前血管活性肠肽）的生物合成过程，我们针对前体分子的五个功能结构域制备了抗血清：前血管活性肠肽22 - 79、肽组氨酸甲硫氨酸（PHM）、前血管活性肠肽111 - 122、血管活性肠肽和前血管活性肠肽156 - 170。这些抗血清用于通过放射免疫分析（RIA）结合高压液相色谱（HPLC）对血管活性肠肽前体肽进行定量和表征，并通过免疫细胞化学检查它们的细胞定位和共定位。所有这五种肽均有表达，但并非如前体氨基酸序列所预期的那样以等摩尔量表达。然而，它们之间的比例在整个胃肠道中相当恒定。唯一的例外是胃窦中PHM和前血管活性肠肽111 - 122的浓度较低，这可以用该区域中大量存在的PHV（PHM的C末端延伸形式，包括前血管活性肠肽111 - 122）来解释。还发现前血管活性肠肽的C末端赖氨酸残基在加工过程中未被去除。免疫细胞化学显示，所有源自前血管活性肠肽的肽都存在于神经元成分中。它们在整个肠道中分布相似，表明共存，这一发现得到了双重染色的支持。这些发现表明，人肠道神经元亚群中前血管活性肠肽的翻译后加工存在差异。
