ABSTRACT
Ameloblastin (Ambn) is an intrinsically disordered protein (IDP) with a specific function of forming heterogenous homooligomers. The oligomeric function is led through a specific sequence encoded by exon 5 of Ambn. Due to the IDP character of Ambn to form oligomers, protein purification is subject to many challenges. Human ameloblastin (AMBN) and its two isoforms, I and II have already been purified as a recombinant protein in a bacterial expression system and functionally characterized in vitro. However, here we present a new purification protocol for the production of native AMBN in its original formation as a homooligomeric heterogeneous IDP. The purification process consists of three chromatographic steps utilizing His-tag and Twin Strep-tag affinity chromatography, along with size exclusion and reverse affinity chromatography. The presented workflow offers the production of AMBN in sufficient yield for in vitro protein characterizations and can be used to produce both AMBN isoforms I and II.
Subject(s)
Dental Enamel Proteins , Intrinsically Disordered Proteins , Humans , Chromatography, Affinity/methods , Exons , Recombinant Proteins/biosynthesis , Intrinsically Disordered Proteins/biosynthesis , Dental Enamel Proteins/biosynthesisABSTRACT
The information concerning problems of occupational allergic rhinitis is given. The whole problem has been followed mainly since 1996 when the amendment with the List of Occupational Diseases was adopted. The List enables to report the separate allergic rhinitis as occupational disease. The data of an account of 24 patients who were reported occupational allergic rhinitis by means of the Department of Occupational Diseases of University Hospital in Hradec Králové during the years 1996-2000 are presented. The author calls attention to the need of precise diagnostics and mainly to benefit of specific nasal provocation tests when examining occupational etiology of diseases. The most frequently affected occupations were bakers, employees of the agricultural animal and vegetable production, textile workers and health care workers. The most frequent allergens are flour, agricultural animal and vegetable allergens, textile dust, izocyanates and disinfectants. Early diagnostics of occupational rhinitis, followed with re-allocation patients from the primary allergenetic environment is emphasized, with the aim to prevent development of bronchial asthma.
Subject(s)
Occupational Diseases/epidemiology , Rhinitis, Allergic, Perennial/epidemiology , Adult , Czech Republic/epidemiology , Female , Humans , Male , Middle Aged , Occupational Diseases/etiology , Occupations , Rhinitis, Allergic, Perennial/etiologyABSTRACT
The present paper demonstrates by documentary evidence occupational diseases caused by chromium and its compounds. Perforations of the nasal septum were diagnosed in 20 males and 9 females, the last one in 1980. Most of them worked in chromium-plating shops. Other diseases, including bronchial asthma, allergic rhinitis, and contact allergic eczemas, were examined in 1985-1999. Bronchial asthma was reported in a textile dyer who was in contact with chromium dyes for 32 years and two allergic rhinitides (a welder and an electroplater) were reported in 1987 as "other damage to health resulting from work." Out of 103 contact allergic eczemas, only 24 diseases, i.e. less than one quarter, were healed in 1999. Improvements were observed in 59 of them and 20 diseases persist. There was an exceptional finding of a chromium ulcer (pigeonneaux) on the lower extremity of a builder.
