Some properties of a ficin-papain inhibitor from avion egg white

Sen, Lourminia C.; Whitaker, John R.

doi:10.1016/0003-9861(73)90554-7

Cited by 56 publications

(24 citation statements)

References 37 publications

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“…The mechanism was not investigated, but if it had been purely competitive, the true K, would have been about 3 x 10-12M. Sen & Whitaker (1973) reported that the inhibition of ficin by cystatin is non-competitive and the K, is much greater than the values we have obtained for papain, cathepsin B and cathepsin L. Their conclusions are invalidated, however, by the fact that the experiments were done with Et (total enzyme concn.) much greater than K,, whereas Et should be less than one-tenth K, for the type of replot used [as discussed by Henderson (1972)].…”

Section: Properties Ofcystatincontrasting

confidence: 56%

“…Cysteine proteinases are abundant in the body, however, and are responsible for much of the intracellular proteolysis (Kirschke et al, 1980), so the means by which their activities are controlled are of great interest. A low-Mr protein that inhibits ficin, papain, cathepsin B and dipeptidyl peptidase I (cathepsin C) has previously been isolated in small quantities from chicken egg white (Fossum & Whitaker, 1968;Sen & Whitaker, 1973;Keilova & Tomasek, 1974). This protein, for which we have proposed the name 'cystatin' (Barrett, 1981), is of particular interest for several reasons.…”

mentioning

confidence: 97%

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Cystatin, a protein inhibitor of cysteine proteinases. Improved purification from egg white, characterization, and detection in chicken serum

Xuereb-Anastasi¹,

Brown²,

Kembhavi³

et al. 1983

Biochemical Journal

300

189

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The protein from chicken egg white that inhibits cysteine proteinases, and has been named 'cystatin', was purified by ovomucin precipitation, affinity chromatography on carboxymethylpapain-Sepharose and chromatofocusing. The final purification step separated two major forms of the protein (pI 6.5 and 5.6), with a total recovery of about 20% from egg white. By use of affinity chromatography and immunodiffusion it was shown that the inhibitor is also present at low concentrations in the serum of male and female chickens. Tryptic peptide maps of the separated forms 1 and 2 of egg-white cystatin were closely similar, and each form had the N-terminal sequence Ser-Glx-Asx. The two forms showed complete immunological identity, and neither contained carbohydrate. Ki values for the inhibition of cysteine proteinases were as follows: papain (less than 1 X 10(-11)M), cathepsin B (8 X 10(-10)M), cathepsin H (about 2 X 10(-8)M) and cathepsin L (about 3 X 10(-12)M). Some other cysteine proteinases, and several non-cysteine proteinases, were found not to be significantly inhibited by cystatin. The inhibition of the exopeptidase dipeptidyl peptidase I by cystatin was confirmed and the Ki found to be 2 X 10(-10)M. Inhibitor complexes with active cysteine proteinases and the inactive derivatives formed by treatment with iodoacetate, E-64 [L-trans-epoxysuccinylleucylamido(4-guanidino)butane] and benzyloxycarbonylphenylalanylalanyldiazomethane were demonstrated by isoelectric focusing and cation-exchange chromatography. The complexes dissociated in sodium dodecyl sulphate/polyacrylamide-gel electrophoresis (with or without reduction) with no sign of fragmentation of the inhibitor. Cystatin was found not to contain a free thiol group, and there was no indication that disulphide exchange plays any part in the mechanism of inhibition.

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Section: Properties Ofcystatincontrasting

confidence: 56%

mentioning

confidence: 97%

Cystatin, a protein inhibitor of cysteine proteinases. Improved purification from egg white, characterization, and detection in chicken serum

Xuereb-Anastasi¹,

Brown²,

Kembhavi³

et al. 1983

Biochemical Journal

300

189

View full text Add to dashboard Cite

show abstract

“…The name cystatin was first used by Barrett [28] to describe an inhibitor that had been discovered and partially characterized from chicken egg-white of papain, ficin and other related cysteine endopeptidases [29]. When other protein inhibitors of cysteine proteinases were characterized and their amino acid sequences determined, it became apparent that they are related to chicken cystatin, and thus they are members of the cystatin superfamily [1 11.…”

Section: Rke Aegpvvyaovdclgcv-~~-hplslo §Pdlepllr~glovfnnnlo~sslfmln~mentioning

confidence: 99%

The cystatins: Protein inhibitors of cysteine proteinases

1991

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The iast decade has witnessed enormous progress of protein inhibitors of cysteine proteinases concerning their structures, functions and evolutionary relationships. Although they differ in their molecular properties and biological distribution, they are structurally related proteins. All three inhibitory families, the stetins, the cystatins and the kininogens, are members of the same superfamily. Recently determined crystal structures of chicken cystatin and human stefin B established a new mechanism of interaction between cysteine proteinases and their inhibitors which is fundamentally different from the standard mechanism for serine proteinases and their inhibitors.

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“…Cystatin is stable under these conditions [29]. Equal amounts of sample (determined by protein concentration) were incubated with 20 FL of 10 m M papain (Sigma Chemical Co., St. Louis, MO).…”

Section: Northern Blot Analysismentioning

confidence: 99%

Increased expression of cathepsins L and B and decreased activity of their inhibitors in metastatic, ras‐transformed NIH 3T3 cells

Chambers

Colella

Denhardt

et al. 1992

Molecular Carcinogenesis

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We previously found that the T24 Ha-ras oncogene induces metastatic ability in NIH 3T3 cells and that this change depends on expression of the ras oncogene. As part of our studies on mechanisms by which ras may induce metastasis, we investigated expression and activity of two cysteine proteinases, cathepsin L (major excreted protein) and cathepsin B, as well as cysteine proteinase inhibitor activity, in ras-transformed NIH 3T3 cells. In a series of cel lines that expressed differing amounts of ras, we found a good correlation between levels of ras expression and cathepsin L expression (r = 0.80). There was also a good correlation between secreted procathepsin L protein levels and experimental metastatic ability (r = 0.88). We found a similar but less strong association between cathepsin B levels and metastatic ability in these cells (r = 0.76 and r = 0.72 for 2.2-kb and 4.1-kb transcripts, respectively). Functional cathepsin L plus B activity (both secreted and cell-associated) was found to be higher in ras-transformed cells and was dependent on cell confluency in culture. Coupled with increased expression and activity of cysteine proteinases, ras-transformed NIH 3T3 cells showed reduced cysteine proteinase inhibitor activity. We conclude that the balance between expression of cysteine proteinases and their inhibitors may be coregulated by ras expression. Our results suggest that ras-induced increases in production of degradative enzymes such as cathepsins L and B, along with decreased activities of their inhibitors, may contribute to the increased malignant properties of ras-transformed NIH 3T3 cells.

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Some properties of a ficin-papain inhibitor from avion egg white

Cited by 56 publications

References 37 publications

Cystatin, a protein inhibitor of cysteine proteinases. Improved purification from egg white, characterization, and detection in chicken serum

Cystatin, a protein inhibitor of cysteine proteinases. Improved purification from egg white, characterization, and detection in chicken serum

The cystatins: Protein inhibitors of cysteine proteinases

Increased expression of cathepsins L and B and decreased activity of their inhibitors in metastatic, ras‐transformed NIH 3T3 cells

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