![]() ![]() This keeps the MMPs in a latent state until the cysteine-Zn 2+ interaction is disrupted then, the Zn(II) ion can combine with water molecules which are necessary for the hydrolysis of polypeptides. The α(3)-helices are followed by a “cysteine switch”, a very conserved region (PRCGXPD), where the sulfhydryl group is coordinated with the catalytic Zn(II) ion, forming a tetrahedral coordination sphere. ![]() The propeptide consists of about 80 amino acid residues forming three α-helices. Furthermore, the methods so far employed for investigating and regulating collagenases and their inhibitors are reviewed. The catalytic mechanism of collagen hydrolysis by collagenases is described. Herein, the family classification and structural characteristics of collagenases (MMPs and bacterial collagenases) are summarized. To fully exploit the potential of enzymatic unhairing, it is crucial to understand the action and effect of components with collagenase activity on different collagen types in the hide and skin. It has been noted that the main risk of grain damage during enzymatic unhairing is due to the over-hydrolysis of collagens by collagenases. A wide range of enzymes have been investigated for their potential applications in enzymatic unhairing, such as alkaline proteinases from Bacillus, keratinases from Actinomadura keratinilytica, and serine proteases from Caldicoprobacter algeriensis. As a reliable alternative to the conventional lime-sulfide process, unhairing by proteases (enzymatic unhairing) in the leather-making process has been employed over decades. However, the conventional hair-burning unhairing process will cause seriously pollution problem. Unhairing is an essential process in leather manufacturing. In the Merops peptidase database, bacterial collagenases and MMPs belong to the M9 family and the M10 family, respectively. Bacterial collagenases are mainly secreted by micro-organisms such as Clostridium and Vibrio. They have the potential to decompose polypeptides in the ECM and play an important role in physiological and pathological processes. MMPs are a family of multi-domain proteolytic enzymes containing zinc ions. The most widely studied collagenases are matrix metalloproteinases (MMPs) from animals and bacterial collagenases from micro-organisms. ![]() ![]() Native type I collagen is highly resistant to common proteases, such as trypsin and chymotrypsin, while enzymes with collagenolytic activity, such as matrix metalloproteinase-1 (MMP-1 also known as interstitial collagenase), show the ability to cleave type I collagen at the triple-helical domain. The most abundant collagen is type I collagen, whose molecule consists of three α polypeptides (two α 1(I)-chains and one α 2(I)-chain) that are wound around each other to form a triple helix, and at either end of the triple helix are non-helical moieties, called telopeptides (Fig. The hide and skin of mammalians consist of various type of collagens, such as types I, III, IV and VII, among which type I and type III collagens are the major types of fibrillar collagen. Fibrillar collagens have high thermal stability and strong mechanical strength. These genes form at least 28 different collagen molecules, fibrillar or non-fibrillar molecules, which are sequentially numbered using Roman numerals (I–XXVIII). To date, 40 vertebrate collagen genes have been identified. Collagens are important components of the extracellular matrix (ECM) in mammalian tissues such as skin, ligaments and tendons. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |