The isolation and characterization of a new elastase inhibitor, pre-alpha 2-elastase inhibitor, of the horse.

The research explores and identifies a new elastase inhibitor present in horse serum, termed as pre-alpha 2-elastase inhibitor. This inhibitor is unique when compared to other known human serum inhibitors on biochemical and immunological aspects.

Research Methodology and Findings

• The scientists first identified this new elastase inhibitor in horse serum. The substance was then purified until it reached a state of homogeneity and was named the pre-alpha 2-elastase inhibitor.
• The electrophoretic migration of the substance was observed to halt before the alpha 2 position, hence its name.
• The molecular weight of the inhibitor was determined to be 188,000 using pore limit polyacrylamide gel electrophoresis and 225,000 by Sephadex G-200 gel filtration. This shows the substance is a high molecular weight protein.
• The inhibitor was found to comprises at least two non-identical polypeptide chains with molecular weights of 68,400 and 87,600 respectively.
• Through the process of isoelectric focusing, it was determined that the substance’s banding pattern focused between pH 4.9 and 5.2, revealing a limited range of heterogeneity.
• The inhibitor was tested against 13 different animal, microbial, and plant proteinases, where it was found to efficiently inhibit pancreatic elastase and trypsin. It had a minimal effect on chymotrypsin, pointing to its selectivity in action.
• The study found that this newly discovered elastase inhibitor has no perceived similarity to known human serum inhibitors based on immunological and biochemical criteria. This suggests the uniqueness of this inhibitor.

Significance

• The discovery of a new elastase inhibitor adds to the current knowledge of these substances. It widens the understanding about the diversity of enzymes and their inhibitors present in different species.
• The unique nature of the pre-alpha 2-elastase inhibitor and its inhibitory action on specific proteases contributes to the understanding of host defense mechanisms in horses, which could have possible implications for equine health and disease.
• The lack of analogy to human serum inhibitors suggests that the animal and human biochemical mechanisms may vary, providing scope for further comparative investigations.