Noncatalytic protein component of elastase from horse leucocytes. A protein with regulatory function.

This research investigates the role of a protein component of elastase in horse leucocytes, finding that it seems to regulate the enzyme’s elastin-dissolving properties.

Protein Identification and Isolation

• The researchers identified a noncatalytic protein component (NPC) as part of the native elastase enzyme found in horse leucocytes (white blood cells). This protein is strongly acidic, with a pH level of 4.5.
• This NPC was isolated from the native elastase for further study and characterization.

Regulatory Function of the Protein

• The study found that the NPC appears to regulate the elastase enzyme by reducing its elastinolytic properties. Elastinolytic refers to the ability to break down elastin, a key protein that helps tissues in the body resume their shape after stretching or contracting.
• The regulatory effect of the NPC occurs potentially by decreasing the isoelectric points of elastase types 1 and 2A. Isoelectric point refers to the pH at which a particular molecule carries no net electrical charge.

Implications and Potential Role

• The high affinity of elastase 1 for NPC rather than for elastin suggests a possible regulatory role for the NPC. Affinity in this context refers to the degree to which the enzyme (elastase 1) prefers to bind with the NPC rather than its usual target (elastin).
• This higher affinity suggests that the NPC might control the activity of elastase 1, and potentially other types of elastase, by binding to the enzyme and reducing its ability to target and break down elastin.