Baumbach G A, Climer A H, Bartley N G, Kattesh H G, Godkin J D
Department of Animal Science, College of Veterinary Medicine, University of Tennessee, Knoxville 37901.
Biol Reprod. 1988 Dec;39(5):1171-82. doi: 10.1095/biolreprod39.5.1171.
The major basic protein (BP) synthesized and secreted by elongating pig blastocysts was purified from medium of Day 14-17 conceptus cultures. Sequential ion-exchange and gel-filtration chromatographies resulted in isolation of BP as a single polypeptide of Mr = 43,100 or 42,800 under denaturing or native conditions, respectively. BP was found to be a glycoprotein by incorporation of [3H] glucosamine and susceptibility to N-glycopeptidase F. Two BP polypeptides were produced by N-glycopeptidase F (Mr = 39,800 and 36,300). Antiserum to BP immunoprecipitated radiolabeled BP from blastocyst culture medium. BP was not detected in medium from 1-2 mm diameter spherical (Day 10) blastocysts but was found in medium from 3-5 mm spherical (Day 10) and filamentous (less than 50 cm, Day 12) conceptuses, suggesting that BP synthesis and secretion began at the initiation of trophoblast expansion. With immunocytochemical procedures, BP was located in the apical cytoplasm of trophectoderm cells of Day 11 expanding (5-7 and 10-20 mm) blastocysts. These results suggest that trophoblast epithelium secrete BP apically toward the uterine lumen and that BP may play a role in maternal-fetal interactions during the peri-implantation period.
从第14 - 17天妊娠产物培养液中纯化出由伸长的猪胚泡合成并分泌的主要碱性蛋白（BP）。通过连续离子交换和凝胶过滤色谱法，分别在变性或天然条件下，将BP分离为分子量为43,100或42,800的单一多肽。通过掺入[3H]葡糖胺和对N - 糖肽酶F敏感，发现BP是一种糖蛋白。N - 糖肽酶F产生了两种BP多肽（分子量分别为39,800和36,300）。针对BP的抗血清从胚泡培养液中免疫沉淀出放射性标记的BP。在直径1 - 2毫米的球形（第10天）胚泡的培养液中未检测到BP，但在直径3 - 5毫米的球形（第10天）和丝状（长度小于50厘米，第12天）妊娠产物的培养液中发现了BP，这表明BP的合成和分泌始于滋养层扩张开始时。通过免疫细胞化学方法，在第11天正在扩张（5 - 7毫米和10 - 20毫米）的胚泡的滋养外胚层细胞的顶端细胞质中定位到了BP。这些结果表明，滋养层上皮向子宫腔顶端分泌BP，并且BP可能在着床前期的母胎相互作用中发挥作用。
