Purification and characterization of a serine protease (esterase B) from rat submandibular glands.

Abstract

A new protease has been purified to homogeneity from rat submandibular gland homogenate by using DEAE-Sephadex chromatography, chromatofocusing, aprotinin-Sepharose affinity chromatography, and high-performance liquid chromatography. The enzyme has been named esterase B, since it represents the second major esterolytic peak on DEAE-Sephadex chromatography of submandibular gland homogenate. It is an acidic protein (pI = 4.45) with an apparent molecular weight of 27 000. It is heat-stable and has an optimum pH of 9.5. Esterase B hydrolyzed the synthetic substrates tosyl-L-arginine methyl ester and Val-Leu-Arg-p-nitroanilide (S2266). It also cleaved dog plasma kininogen to produce a kinin, identified as bradykinin on reverse-phase high-performance liquid chromatography. Esterase B, however, is only a weak kininogenase, since it had only 5% of the kininogenase activity of equimolar concentrations of glandular kallikrein and had no effect on rat mean blood pressure or on the isolated rat uterus. Esterase B activated plasminogen and had caseinolytic activity. It was inhibited by aprotinin, soybean trypsin inhibitor, lima bean trypsin inhibitor, phenylmethanesulfonyl fluoride, antipain, leupeptin, and p-tosyl-L-lysine chloromethyl ketone. On double immunodiffusion, when reacted with kallikrein and tonin antisera, esterase B showed partial identity with kallikrein but not with tonin. On immunoelectrophoresis against kallikrein antisera, esterase B formed a precipitin arc at a position different from that of kallikrein. Esterase B appears to be a trypsin-like serine protease having some homology with glandular kallikrein.

• Authors: M Khullar, G Scicli, O A Carretero, A G Scicli
• Journal: Biochemistry (Biochemistry) Vol. 25 Issue 8 Pg. 1851-7 (Apr 22 1986) ISSN: 0006-2960 [Print] United States
• PMID: 3085708 (Publication Type: Journal Article, Research Support, U.S. Gov't, P.H.S.)

Chemical References

• Amino Acids
• Endopeptidases
• Kallikreins
• Serine Endopeptidases
• esterase B

Topics

• Amino Acids (analysis)
• Animals
• Endopeptidases (isolation & purification, metabolism)
• Immunodiffusion
• Kallikreins (metabolism)
• Kinetics
• Male
• Molecular Weight
• Rats
• Rats, Inbred Strains
• Serine Endopeptidases
• Submandibular Gland (enzymology)
• Substrate Specificity