Hemocyanin a Most Likely Inducer of Black Spots in Kuruma Prawn <i>Penaeus japonicus</i> During Storage

Adachi, Kohsuke; Hirata, Takashi; Nagai, Kazuya; Sakaguchi, Morihiko

doi:10.1111/j.1365-2621.2001.tb16093.x

Cited by 66 publications

(48 citation statements)

References 30 publications

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“…32 Kuruma prawn (Penaeus japonicas) hemocyanin can also gain the phenolase activity by the addition of sodium dodecyl sulfate to the solution. 33 However, these activation processes are so complicated that neither the regulation process of the enzymatic functions nor the mechanism of the phenolase and catecholase activities had been addressed in detail.…”

Section: Introductionmentioning

confidence: 99%

Controlling Dicopper Protein Functions

Fujieda¹,

Itoh²

2016

Bulletin of the Chemical Society of Japan

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Maturation processes of dinuclear copper proteins such as tyrosinase, catechol oxidase, and hemocyanin have been a long-standing mystery in copper protein chemistry. Until now, several crystal structures have revealed that these copper proteins share a similar dinuclear copper active site, where each copper ion is ligated by three histidine imidazoles, and binds molecular oxygen in a side-on fashion to form a (¯-η 2 :η 2 -peroxido)dicopper(II) species not only as the dioxygen-adduct in oxy-hemocyanins but also as the key reactive intermediate for the hydroxylation of phenols to catechols (phenolase reaction) and the oxidation of catechols to o-quinones (catecholase reaction) in tyrosinases and catechol oxidases. Recently, we have succeeded in determining the high-resolution crystal structures of the recombinant pro-form of yellow koji mold tyrosinase to find the existence of a distinct C-terminal domain containing a CXXC unit, that is the common sequence motif of the copper chaperons. Thus, the C-terminal domain apparently acts as a copper chaperon, helping construction of the dinuclear copper active site of tyrosinase. Furthermore, we have found that the proteolytic cleavage of the C-terminal domain from the pro-form (inactive-form) of tyrosinase greatly enhances the tyrosinase activity, thus suggesting that the Cterminal domain also acts as a shielding domain to regulate the enzymatic activity. In fact, overall structure of the pro-form resembles the structure of one of the functional units of octopus hemocyanin (oxygen carrier protein), which also has a similar C-terminal domain prohibiting the monooxygenase activity. On the basis of these results together with the detailed kinetic and spectroscopic analyses, the maturation process of the dinuclear copper proteins is discussed to provide new insights into the regulation mechanism of the dicopper protein functions; dioxygen binding and activation. We have also succeeded in evolving phenolase activity from molluscan and arthropod hemocyanins by treating them with a hydrolytic enzyme or an acid, and demonstrated that the reaction mechanism of their phenolase activity is the same to that of tyrosinase itself, that is the electrophilic aromatic substitution mechanism. Furthermore, we have developed an artificial dicopper protein exhibiting catecholase activity using metallo-β-lactamase, a dinuclear zinc enzyme, as a metal binding platform.

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Section: Introductionmentioning

confidence: 99%

Controlling Dicopper Protein Functions

Fujieda¹,

Itoh²

2016

Bulletin of the Chemical Society of Japan

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“…The melanosis-inhibiting effect of 4-hexylresorcinol accompanied by several organic acids and chelating agents, has also been reported in prawns (Montero et al, 2001). Adachi et al (2001) have also reported a significant and rapid development of black spots in Kuruma prawn after thawing. Shrimp treated with 4-hexylresorcinol showed the best appearance during conservation, with only a slight melanosis over a minimum of 8 days.…”

Section: Organoleptic Analysismentioning

confidence: 88%

Contribution to the Revision of the Senegalese Law on the Use of Sulfites for the Treatment of Crustaceans: the Case of Shrimp

Diouf¹,

Fall

Ayessou³

et al. 2016

JBLS

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Shrimp, by its considerable economic importance, is the second shellfish species exported in Senegal. Blackening of untreated sulfites shrimp causes discharges estimated at 10% of the total landed shrimp according to the shrimp processing plant companies. Health problems caused by handling and / or consumption of sulphites (asthmatic subjects) occured. residues could cause Technical trade Barriers in international exchanges. In Senegal, the Competent Authority (CA), a part of its mission of monitoring and inspection of fish products, especially shrimp, cooperate with two chemistry laboratories for detecting residues of SO2. However, the differences noted on the results provided by these two laboratories (Lab1 and 2) make difficult interpretations. This study aims to remove existing ambiguities on the analyzes and interpretation of results regarding to national and community regulations. During the study, more investigations and analyzes of archival data, samples of untreated and treated shrimp sodium metabisulfite were analyzed respectively in the laboratory of the Division of Inspection and Control (DIC) to assess blackening and laboratories 1, 2 and 3 for the detection of residual sulphite in shrimp. Firstly, the results show that the shrimp processing and regulations governing the residual SO2 levels in their flesh can not be effective without taking account of their caliber, and secondly, that the divergence of results provided by the Labo-1 and 2 is more methodological. Thus, the study calls for regulatory oversight in order to harmonize national and international regulations governing the residual SO2 levels in shrimp. It also recommends the creation of a common reference for the determination of residues of SO2 in the flesh of shrimp.

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“…The second showed conversely that Hc in crabs and lobsters has o-diphenol oxidase activity when treated with perchlorate [10]. In 2001, based on those two facts, prawn Hc was shown to be converted into a PO-like enzyme by dodecyl sodium sulphate (SDS) [9]. In addition, this catalytic activity is very stable and is maintained over two months under frozen conditions, while PO loses its activity within a week under the same conditions ( Fig.…”

Section: The Relationship Of Po and Melanogenesis In Prawnsmentioning

confidence: 94%

“…The effects of the freeze-thawing process on this system remain unclear, but it is believed that this system is strictly controlled in the living body and breaks down post-mortem to spontaneously activate proPO to PO. difficult [7][8][9]. The details of characterisation of proPO are described by Cerenius and Söderhäll [3].…”

Section: Biochemical Characterisation Of Propo and Pomentioning

confidence: 99%