Conversion of pepsinogen into pepsin is not a one-step process

Dykes, Colin W.; Kay, John

doi:10.1042/bj1530141

Cited by 62 publications

(27 citation statements)

References 10 publications

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“…This showed that the exogenous pepsin attacked the pepsinogen The activation of porcine pepsinogen A in solution proceeded through two different pathways, i.e. one-step pathway and a sequential pathway [2,5,61. As shown in Fig.…”

Section: ~I Y K V P L V R K K S L R R N L S E H G L L K D F L K K H Nmentioning

confidence: 99%

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Activation mechanism of monkey and porcine pepsinogens A. One-step and stepwise activation pathways and their relation to intramolecular and intermolecular reactions

Kageyama

Takahashi

1987

Eur J Biochem

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The activation of Sepharose-bound monkey pepsinogen A under acidic conditions proceeded by cleavage of the L e~~~-I l e~' bond, indicating the occurrence of the intramolecular one-step activation, although the rate of cleavage was very slow. On the other hand the activation of monkey pepsinogen A in solution was highly dependent on pepsinogen concentration and the addition of exogenous pepsin A accelerated the rate of activation, indicating the predominance of intermolecular reaction. The cleavage site, however, was also restricted to the L e~~~-I l e~' bond. Thus, apparently exclusive one-step activation occurred in monkey pepsinogen. The activation of porcine pepsinogen A in solution was also dependent on pepsinogen concentration and the addition of exogenous pepsin A accelerated the rate of activation. The major cleavage site by the exogenously added pepsin was the L e~~~-I l e~~ bond. Therefore the site most susceptible to the intermolecular attacks was the bond connecting the activation segment and the pepsin moiety in both monkey and porcine pepsinogens. In porcine pepsinogen, however, a part of the zymogen was activated through the intermediate form, and an intramolecular reaction was suggested to be involved in the generation of this form.These results showed that in both pepsinogens A the intramolecular reaction occurred, first yielding pepsin A or the intermediate form, which then acted intermolecularly on the remaining pepsinogen or the intermediate form to complete the activation in a short time. A molecular mechanism for the activation reaction was proposed to explain consistently the experimental results.Pepsinogen is converted to pepsin under acidic conditions by releasing the so-called activation peptides from its NH2-terminal part. Two pathways are known for the activation, i.e. a one-step (direct conversion) pathway and a stepwise (sequential conversion) pathway. Monkey pepsinogen A has been shown to be activated nearly exclusively by the one-step pathway releasing the intact 47-residue activation segment [l] (see Fig. 1). This pathway has also been shown to occur in the activation of porcine [2], rabbit [3] and chicken [4] pepsinogens A, although in porcine and rabbit pepsinogens sequential pathways occurred simultaneously [2,3,5,6]. Contrary to these pepsinogens, the activation of bovine prochymosin [7], and human

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Section: ~I Y K V P L V R K K S L R R N L S E H G L L K D F L K K H Nmentioning

confidence: 99%

“…1). This pathway has also been shown to occur in the activation of porcine [2], rabbit [3] and chicken [4] pepsinogens A, although in porcine and rabbit pepsinogens sequential pathways occurred simultaneously [2,3,5,6]. Contrary to these pepsinogens, the activation of bovine prochymosin [7], and human …”

mentioning

confidence: 99%

Activation mechanism of monkey and porcine pepsinogens A. One-step and stepwise activation pathways and their relation to intramolecular and intermolecular reactions

Kageyama

Takahashi

1987

Eur J Biochem

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“…The two activation segments show a pronounced homology, especially in the first 27 amino acid residues (Fig.l), but in spite of this, peptides of different sizes are released during the initial limited proteolysis. During activation of porcine pepsinogen at pH 2 the bond Leu-Ile (18 -19) is cleaved first [6,7] while the peptide comprising residues 1 -27 was isolated after activating prochymosin at pH 2 [8]. Furthermore, as another difference from the activation of prochymosin, Bustin and ConwayJacobs [9] and Al-Janabi et al [lo] have found that the conversion of porcine pepsinogen into pepsin occurs mainly as an intramolecular (first-order) reaction at pH 2.…”

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confidence: 99%

Investigations on the Activation of Bovine Prochymosin

Pedersen

Christensen

Foltmann

1979

European Journal of Biochemistry

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Activation of prochymosin at pH below 2.5 results in formation of the active enzyme pseudochymosin by proteolytic cleavage of the bond 27-28. Pseudochymosin is 15 amino acid residues longer than chymosin. It is the final activation product at low pH, whereas chymosin is formed by activation between pH 4 and 5. Pseudochymosin is converted to chymosin when it is brought to pH 5.5.Our present knowledge does not allow quantitative evaluation of the possible reactions involved in formation of pseudochymosin, but the course of activation at pH 2 is in accordance with an intermolecular reaction between two zymogen molecules as the predominant reaction. We find indications of an intramolecular reaction when intermolecular reactions are prevented by immobilization of the zymogen.

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“…The formation of a metastable intermediate during the activation process appears to indicate that the activation of procathepsin D-I1 occurs in two steps. A similar type of activation has also been suggested in the case of porcine pepsinogen [27,28]. Procathepsin D-I1 apparently showed an increasing affinity to pepstatin-Sepharose, as the pH was decreased from 5 to 3.…”

Section: Discussionmentioning

confidence: 69%

Identification of Monkey Lung Procathepsin d‐II as a Pepsinogen‐C‐Like Acid Protease Zymogen

Moriyama

Kageyama

Takahashi

1983

European Journal of Biochemistry

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Procathepsin D-I1 (Mr=37500) was purified from Japanese monkey lung at pH 7.0, and was shown to be converted to the active form, cathepsin D-I1 (M,= 33000) via an intermediate ( M , = 35 500) upon treatment at pH 3.0 and 14 "C. Procathepsin D-I1 was shown to be the inactive precursor of cathepsin D-I1 based on the following results: the former was inactive toward heat-denaturated casein at pH 5.4 whereas the latter was active; the former was not inactivated by diazoacetyl-DL-norleucine methyl ester in the presence of Cu2+ ion at pH 6.0 whereas the latter was inactivated rapidly under the same conditions; and the former had no affinity to pepstatin-Sepharose between pH 5 and 7 whereas the latter was adsorbed to it.With a rabbit antiserum against procathepsin D-11, cathepsin D-11, pepsinogen C and pepsin C of Japanese monkey were each found to give a single precipitin line which fused completely with each other on agarose plate. On the other hand, cathepsin D-I purified from the monkey lung, and pepsinogens A (I, 11, 111-1, 111-2 and 111-3) obtained from the monkey gastric mucosa failed to precipitate with the antiserum. With the antiserum against the monkey pepsinogen C, the same results were obtained. Cathepsin D is an intracellular acid protease normally present in lysosomes [ 11, whereas pepsin is an extracellular acid protease, which is secreted from the gastric mucosa as its precursor form and then autocatalytically activated by acid [2]. Previously we purified a unique acid protease, designated as cathepsin D-11, from monkey lungs [3,4]. It was shown to be more similar to pepsin C than to ordinary cathepsin D and pepsin A in several enzymatic properties, and its amino acid composition was strikingly similar to that of pepsinogen C. These findings led us to investigate further the relationship between cathepsin D-I1 and pepsin C.I n this paper, we present evidence for the presence of the inactive precursor of cathepsin D-11, namely procathepsin D-11, and its conversion to the active form under acidic conditions, and for their strong similarities in immunological and structural properties to pepsinogen C and pepsin C. MATERIALS AND METHODS Mat er i d sMonkey procathepsin D-11 ( M , = 37 500) was purified from Japanese monkey lung by a modification of the procedure previously used for monkey cathepsin D-I1 [4]. The ammonium sulfate fractionation step was omitted and all chromatographies were performed at pH 7.0. The buffer used Abbreviations. N,CHCO-Nle-OMe, diazoacetyl-DL-norleucine methyl ester; NaDodSO,, sodium dodecyl sulfate. In the pepsinogen A nomenclature, the Roman numerals in parentheses refer to elution from DEAEcellulose columns.Enzymes. Cathepsin D (EC 3.4.23.5), pepsin A (EC 3.4.23

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Conversion of pepsinogen into pepsin is not a one-step process

Cited by 62 publications

References 10 publications

Activation mechanism of monkey and porcine pepsinogens A. One-step and stepwise activation pathways and their relation to intramolecular and intermolecular reactions

Activation mechanism of monkey and porcine pepsinogens A. One-step and stepwise activation pathways and their relation to intramolecular and intermolecular reactions

Investigations on the Activation of Bovine Prochymosin

Identification of Monkey Lung Procathepsin d‐II as a Pepsinogen‐C‐Like Acid Protease Zymogen

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