Study of zinc protein ligands in a halophilic enzyme

Glucose dehydrogenase (EC 1.1.1.47) from the halophilic Archaeon Haloferax mediterranei belongs to the medium-chain alcohol dehydrogenase superfamily and requires a zinc ion for catalysis. The zinc ion is coordinated by a histidine, a water molecule and two other ligands from the protein or the substrate, which vary during the catalytic cycle of the enzyme. In many enzymes of this superfamily one of the zinc ligands is commonly cysteine, which is replaced by an aspartate residue at position 38 in the halophilic enzyme. This change has been only observed in glucose dehydrogenases from extremely halophilic microorganisms belonging to the Archaea Domain. This paper describes biochemical studies and structural comparisons to analyze the role of sequence differences between thermophilic and halophilic glucose dehydrogenases which contain a zinc ion within the protein surrounded by three ligands. Whilst the catalytic activity of the D38C GlcDH mutant is reduced, its thermal stability is enhanced, consistent with the greater structural similarity between this mutant and the homologous thermophilic enzyme from Thermoplasma acidophilum.

Nile River and Birkat Qārūn Regions, Egypt, 1854 (Raster Image)

This layer is a georeferenced raster image of the historic paper map entitled: Carte hydrographique de la Moyenne Égypte, où sont indiqués les travaux exécutés ou à exécuter, d'après les ordres de Son Altesse Mehémet-Ali, Vice-Roi d'Egypte. Avec le projet de communication directe des deux mers au travers de l'Isthme, par M. Linant de Bellefonds ; gravée par Schwaerzlé et Erhard. It was published by Dépôt de la Guerre in 1854. Scale 1:250,000. Covers a portion of the Nile River region near Birkat Qārūn, Banī Suwayf, Al Fayyūm, and Al Minyā. Map in French.The image inside the map neatline is georeferenced to the surface of the earth and fit to the Egypt Red Belt projected coordinate system. All map collar and inset information is also available as part of the raster image, including any inset maps, profiles, statistical tables, directories, text, illustrations, index maps, legends, or other information associated with the principal map. This map shows features such as drainage, canals, roads, cities and other human settlements, administrative boundaries, ruins and historical sites, and more. Relief shown by hachures. Includes also text and notes.This layer is part of a selection of digitally scanned and georeferenced historic maps from the Harvard Map Collection. These maps typically portray both natural and manmade features. The selection represents a range of originators, ground condition dates, scales, and map purposes.

Hādhihi Taqrīrāt rāʼiqah wa-taḥqīqāt fāʼiqah

nammaqahā Muḥammad al-Azharī najl al-Ḥasan al-ʻAdawī al-Ḥamzāwī. Washshaḥa bihā ḥawāshī Muḥammad al-Ḥifnī ʻalá Sharḥ al-Risālah al-waḍʻīyah al-ʻAḍudīyah / li-Abī al-Qāsim al-Samarqandī wa-bi-hāmishihā al-ḥawāshī al-madhkūrah maʻa al-sharḥ al-madhkūr.

Talfīq al-akhbār wa-talqīḥ al-āthār fī waqāʻiʻ Qāzān wa-Bulghār wa-mulūk al-Tatār

athar M. M. al-Ramzī.

Kitāb Sullam al-ʻulūm wa-ḥāshiyatihi al-mashhūrah bi-al-Qāḍī maʻa minhīyātih

[Muḥibb Allāh ibn ʻAbd al-Shakūr al-Bihārī].

Qānūn dīwān al-rasāʼil: manqūl ʻan nuskhah khaṭṭīyah bi-Maktabat Kambritsh

li-Tāj al-Riyāsah Abī al-Qāsim ʻAlī ibn Munjib ibn Sulaymān al-shahīr bi-Ibn al-Ṣayrafī ; ʻuniya bi-nashrihi wa-al-taʻlīq ʻalayhi ʻAlī Bahjat.

al- Khulāṣah al-naqīyah fī umarāʼ Ifrīqīyah: wa-maʻahu ʻUqūd al-farāʼid fī tadhyīl al-Khulāṣah wa-fawāʼid al-rāʼid lil-muʼallif ayḍan

taʼlīf Abī ʻAbd Allāh Muḥammad al-Bājī al-Masʻūdī.

Nāmūs al-īqān

Kharbūtī Yūsuf Afandī.

Kitāb Qāmūs al-ʻāshiqīn fī akhbār al-Sayyid Ḥusayn Burhān al-Dīn

taʼlīf ʻAbd al-Munʻim al-ʻĀnī thumma al-Rāwī ; [muṣaḥḥiḥuhu Aḥmad ibn Saʻd al-Dīn ibn Muṣṭafá al-Qabbānī].

Hādhihi Tarjamat quṭb al-wāṣilīn wa-ghawth al-sālikīn al-ʻārif billāh Sayyidī Shams al-Dīn Muḥammad Abī al-Maḥāsin al-Qāwuqjī al-Ḥasanī

min qalam ʻAbd al-Qādir al-Adʹhamī al-Ṭarābulusī.