CLONING AND CHARACTERIZATION OF RABBIT PANCREATIC COLIPASE

1. Among the digestive enzymes synthesized by pancreas. lipase is the principle lipolytic enzyme which hydrolyses dietary glycerides. 2. For its action it requires a coenzyme, colipase. 3. The molecular mechani sms of the interaction of these two are not fully understood. 4. Furth er, molecular events that regulate and influence lipid absorption are ill defined. 5. The rabbit is the conventional animal model for the st udy of lipid absorption. We have undertaken the molecular cloning, and characterization of rabbit pancreatic colipase, the coenzyme for panc reatic lipase. 6. Colipase has been cloned from a gt 11 library of an adult rabbit pancreatic cDNA by probing with an oligonucleotide derive d from human colipase sequence.7. The total reading frame consists of 321 nucleotides coding for 90 amino acids of the functional protein an d 17 nucleotides of the leader peptide. 8. Northern blot analysis reve aled a distinct band around 0.5 kb. Comparison with other species reve aled an over all homology of 75% at the nucleotide level. 9. At the am ino acid level highest conservation is observed at the lipase-binding region (AA 53-73). 10. Rabbit enzyme also retained the N-terminal pent apeptide of it preform. 11. The regions of homology and conservation m ay aid to define the sites of interaction of colipase with lipase.