Isolation and properties of prophospholipase A2 and phospholipase A2 from horse pancreas and horse pancreatic juice.

This study isolated two types of enzymes known as phospholipases A2 from horse pancreas in high yield, and found that these enzymes differ from similar enzymes in pigs and cows in terms of their amino acid composition and kinetic properties.

Isolation of the Phospholipases A2 Enzymes

• Two types of enzymes, known as phospholipases A2 (EC 3.1.1.4), were obtained from horse pancreas. These enzymes were found in large quantities, with a yield of 880 milligrams per kilogram of tissue.
• From the pancreatic juice of horses, one specific sense of this enzyme was found in isolation. The researchers referred to this kind as the “sole phospholipase A2.”

The Activation of Zymogens

• The study also found that tryptic activation, a process in which enzymes known as trypsin stimulate the enzyme to its active form, released seven and five peptides respectively from the N-terminal part of the proteins.
• This action led to the formation of a single enzyme with a specific activity higher than that of the same enzymes found in other mammals.

Differences between Horse Enzymes and other Species

• The horse phospholipase A2 enzymes were found to differ from similar enzymes in pigs and cows. These differences concerned their amino acid composition and their kinetic properties, relating to the rates at which these enzymes perform their functions.
• Through automatic Edman degradation, a technique used in protein sequencing, the researchers determined the sequence of the first 41 amino acid residues at the N-terminus of the enzymes, adding to the body of knowledge about these enzymes in horses.