CPA5

Carboxypeptidase A5 is an enzyme that in humans is encoded by the CPA5 gene.

Carboxypeptidases have functions ranging from digestion of food to selective biosynthesis of neuroendocrine peptides. Members of the A/B subfamily of carboxypeptidases, such as CPA5, contain an approximately 90-amino acid pro region that assists in the folding of the active carboxypeptidase domain. Cleavage of the pro region activates the enzyme (Wei et al., 2002).[supplied by OMIM]

References

Further reading

Cathay Pacific Flight 780

Cathay Pacific Flight 780 was a flight from Surabaya Juanda International Airport in Indonesia to Hong Kong International Airport on 13 April 2010. There were 309 passengers and a crew of 13 on board. As Flight 780 neared Hong Kong the crew were unable to change the thrust output of the engines. The aircraft, an Airbus A330-300, landed at almost twice the speed of a normal landing, suffering minor damage. The 57 passengers who sustained injuries were hurt in the ensuing slide evacuation; one of them received serious injuries.

The cause of the incident was contaminated fuel uploaded at Surabaya, which gradually damaged both engines of the aircraft.

The flight's two Australian pilots, Captain Malcolm Waters and First Officer David Hayhoe, who safely landed the aircraft despite the extraordinary challenge, have been compared with Chesley Sullenberger of US Airways Flight 1549. In March 2014, the two pilots were awarded the Polaris Award by the International Federation of Air Line Pilots' Associations, for their heroism and airmanship.

CPA3

Carboxypeptidase A3 (mast cell carboxypeptidase A), also known as CPA3, is an enzyme which in humans is encoded by the CPA3 gene.

Function

Altogether, there are 22-23 members of the metallocarboxypeptidase gene family in most mammals. CPA3 is one of 8-9 members of the A/B subfamily that includes the well-studied pancreatic enzymes carboxypeptidase A1 (CPA1), carboxypeptidase A2 (CPA2), and carboxypeptidase B. This subfamily includes 6 carboxypeptidase A-like enzymes, numbered 1-6. The enzyme now called CPA3 was originally named mast cell carboxypeptidase A, and another protein was initially called CPA3 (Huang et al., 1999). A gene nomenclature committee renamed mast cell carboxypeptidase A as CPA3, and the original CPA3 reported by Huang et al. became CPA4 to reflect the order of their discovery.

CPA3 is secreted from mast cells and has a pH optimum in the neutral to basic range. It resembles pancreatic carboxypeptidases A1 in cleaving COOH-terminal aromatic and aliphatic amino acid residues. CPA3 functions together with endopeptidases secreted from mast cells such as chymases and tryptases to degrade proteins and peptides. Upon mast cell activation and degranulation, CPA3, the chymases, and tryptases are released in complexes with heparin proteoglycan.