[19] Cathepsins

Mycek, Mary J.

doi:10.1016/0076-6879(70)19022-7

Cited by 69 publications

(35 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As some amines can inhibit DPP I [23,24], it is possible pended on the choice of substrate. The pH optimum with GlyPhe-NH-Np was broad with highest activity at 5.5, whilst the that histamine is acting directly on this enzyme.…”

Section: Activation Of Prochymase By Dpp Imentioning

confidence: 99%

The conversion of recombinant human mast cell prochymase to enzymatically active chymase by dipeptidyl peptidase I is inhibited by heparin and histamine

McEuen

Ashworth

Walls

1998

European Journal of Biochemistry

View full text Add to dashboard Cite

Chymase, a major product of mast cell activation, is secreted as a fully active enzyme. We have prepared recombinant human prochymase and have investigated the conditions under which it may be activated by dipeptidyl peptidase I (DPP I). The gene for human chymase was cloned in a baculovirus vector and expressed in High Five insect cells, and the recombinant protein purified by heparin-agarose and gel-filtration chromatography. The purified prochymase was homogeneous by SDS/PAGE with the same molecular mass as native human chymase, and its identity confirmed by N-terminal sequence analysis and Western blotting with chymase-specific antibodies. Treatment with DPP I to remove the Nterminal dipeptide prosequence resulted in enzymatically active chymase, with substrate and inhibitor profiles very similar to those of the native human enzyme. The activation of prochymase by DPP I was strongly inhibited by heparin (IC 50 ϭ 0.5 µg ml Ϫ1 ) and histamine (IC 50 ϭ 2 mM), though these mast cell products had little effect on the action of DPP I towards a low molecular-mass substrate. The pH optimum of DPP I was also higher and narrower with prochymase. The inhibitory action of heparin was lost at NaCl or KCl concentrations sufficient to elute prochymase from a heparin agarose column. Dextran sulphate was as inhibitory as heparin, whereas chondroitin sulphate C was more than 10-fold less effective. Our findings suggest that the activation of prochymase might be restricted to the early stages of vesicle maturation, when the pH is close to neutrality and the histamine and heparin concentrations are low.Keywords : chymase ; dipeptidyl peptidase I; heparin; histamine ; mast cell.Chymase is a serine protease with chymotrypsin-like sub-poprotein B-100, an early step in the aetiology of atherosclerotic strate specificity which is synthesised and stored in the secretory plaques [11]. granules of mast cells along with tryptase (a serine protease with Unlike the digestive proteases trypsin and chymotrypsin, trypsin-like substrate specificity), heparin and histamine [1]. chymase and tryptase, along with other granulocyte proteases, These are released in response to allergens or other stimuli. Al-are not stored as proenzymes, but in forms that are instantly though, in humans, chymase is most abundant in a mast cell active upon release from the secretory granule [1]. However, it subpopulation which predominates in connective tissue, it may is unlikely that proteases would be active in storage. An investialso be present in most, if not all, mast cells in mucosal tissue gation into the factors that might regulate the activity of chy- [2]. This protease has been implicated in defense against helmin-mase within the granule revealed that chymase is relatively inthic parasites, in allergic reactions, in cardiovascular disease, and active at pH 5.5 [12], the reported pH within the mast cell granin chronic inflammatory diseases [3]. Actions attributed to chy-ule [13]. Furthermore, heparin was found to accentuate this efmase include the conversion...

show abstract

Section: Activation Of Prochymase By Dpp Imentioning

confidence: 99%

The conversion of recombinant human mast cell prochymase to enzymatically active chymase by dipeptidyl peptidase I is inhibited by heparin and histamine

McEuen

Ashworth

Walls

1998

European Journal of Biochemistry

View full text Add to dashboard Cite

show abstract

“…As stated previously, the assay used in this investigation is essentially that of Mycek (1970). Two modifications of this procedure were necessary.…”

Section: Discussionmentioning

confidence: 99%

“…Cathepsin Bl is usually assayed using a synthetic peptide substrate such as benzoyl-L-argininamide, but it may be assayed using hemoglobin if cysteine is added to the substrate solution (Mycek, 1970). Although not as specific for cathepsin Bl, this method has the advantage of allowing direct comparison with cathepsin D activity on the same protein substrate.…”

Section: Classificationmentioning

confidence: 99%

“…Cathepsin R is believed to be responsible for the modification and cleavage of newly synthesized proteins and the excision of chains with translational errors (Levyant ~ .s.l,., 1976 (1936). The assay used in the present work is essentially that of Mycek (1970), using hemoglobin as substrate.…”

Section: Classificationmentioning

confidence: 99%

“…The term "cathepsin" (from the Greek meaning "to digest") was first applied in 1929 to tissue proteinase activity at acid pH (Mycek, 1970). Work in the 1930s was conducted under the assumption that this activity was due to a single enzyme.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

The significance of hypovolemia in dehydrational death in anurans

Kimmel¹

View full text Add to dashboard Cite

Molecular components related to egg viability in the gilthead sea bream,Sparus aurata

et al. 2001

View full text Add to dashboard Cite

In pelagic egg spawners, the production of large numbers of sinking eggs, unable to develop into embryos, represents one of the major limiting factors in controlled reproduction. The aim of this study is to elucidate the molecular differences between floating and nonfloating eggs at cytoplasmic and nuclear level. Comparison of analyses between floating and nonfloating sea bream Sparus aurata eggs evidenced differences in vitelline envelope protein components, such differences being probably related with the hydration process but not with fertilization as supported by the assessment of DNA that doubled after in vitro insemination. These data clearly indicated that the absence of embryo development in nonfloating eggs is not due to lack of fertilization. The cytoplasmic composition was also different, the number of protein components being higher in floating eggs, and these extra components may generate the appropriate osmotic pressure at the base of the hydration process. Some lysosomal enzymes, such as cathepsin D and L both involved in yolk proteolysis, in virgin nonfloating eggs were significantly higher with respect to floating ones; the levels of these two enzymes significantly increased in the latter after fertilization. On the contrary, in nonfloating eggs cathepsin L significantly decreased after fertilization. These changes may be related with a series of metabolic processes vital for the production of viable offspring. The capacity of egg transcription and the protein synthesis in these two types of eggs, indicated by the RNA/DNA and RNA/protein ratios, evidenced that the status of cell transcription rate and protein synthesis capacity is significantly higher in floating eggs. This, in turn, suggested that the lack of embryo development may be due to low levels of proteins involved in cell cycle regulation. Mol. Reprod. Dev. 58:330–335, 2001. © 2001 Wiley‐Liss, Inc.

show abstract

[19] Cathepsins

Cited by 69 publications

References 47 publications

The conversion of recombinant human mast cell prochymase to enzymatically active chymase by dipeptidyl peptidase I is inhibited by heparin and histamine

The conversion of recombinant human mast cell prochymase to enzymatically active chymase by dipeptidyl peptidase I is inhibited by heparin and histamine

The significance of hypovolemia in dehydrational death in anurans

Molecular components related to egg viability in the gilthead sea bream,Sparus aurata

Contact Info

Product

Resources

About