Payne R M, Sims H F, Jennens M L, Lowe M E
Department of Pediatrics, Washington University School of Medicine, St. Louis, Missouri 63110.
Am J Physiol. 1994 May;266(5 Pt 1):G914-21. doi: 10.1152/ajpgi.1994.266.5.G914.
We report the cDNA sequences of rat colipase, rat pancreatic lipase (rPL), and a rat pancreatic lipase-related protein (rPLRP). Comparison to the human PLRP cDNA suggests that the isolated clone encodes rPLRP-2. Both cDNA and a third cDNA encoding rPLRP-1 are secreted from Sf9 cells infected with recombinant baculovirus. rPL and rPLRP-2 hydrolyze triolein, 8.0 and 4.4 mumol.min-1.microgram-1, respectively. They are inhibited by bile salts, and activity is restored by (pro)colipase. PLRP-1 has barely detectable activity against triolein, even with (pro)colipase present. The pattern of mRNA expression during development in the rat reveals that all mRNA are low in the fetal rat pancreas. Both PLRP mRNA rise just before birth to a maximum 12 h after birth. They fall to low levels in the adult. In contrast, the PL mRNA is low at birth and rises rapidly during the suckling-weanling transition. In conclusion, the rat has at least three genes encoding different lipases, and these related genes have separate regulatory controls.
我们报道了大鼠共脂肪酶、大鼠胰脂肪酶（rPL）以及大鼠胰脂肪酶相关蛋白（rPLRP）的cDNA序列。与人类PLRP cDNA的比较表明，分离得到的克隆编码rPLRP - 2。编码rPLRP - 1的cDNA和另一个cDNA均由感染重组杆状病毒的Sf9细胞分泌。rPL和rPLRP - 2分别以8.0和4.4 μmol·min⁻¹·μg⁻¹的速率水解三油酸甘油酯。它们受到胆盐的抑制，并且（前体）共脂肪酶可恢复其活性。即使存在（前体）共脂肪酶，PLRP - 1对三油酸甘油酯的活性也几乎检测不到。大鼠发育过程中的mRNA表达模式显示，所有mRNA在胎鼠胰腺中含量都很低。两种PLRP mRNA在出生前刚刚升高，并在出生后12小时达到最大值。在成年后它们降至低水平。相比之下，PL mRNA在出生时含量较低，并在哺乳 - 断奶过渡期迅速升高。总之，大鼠至少有三个编码不同脂肪酶的基因，并且这些相关基因具有独立的调控机制。
