Hyaluronan hyaluronidase

The term hyaluronidase was introduced in 1940 to denote enzymes that degrade hyaluronan. Hyaluronidase has been used by many authors as a synonym... 

The term hyaluronidase was introduced in 1940 to denote enzymes that degrade hyaluronan. Hyaluronidase has been used by many authors as a synonym for spreading factors." This is only partly correct, as all hyaluronidases act as spreading factors, but not all spreading factors are hyaluronidases [1]. 

As an extension of the HA film approach, Yun and coworkers [32] synthesized hyaluronan microspheres using the chemistry described above, but the synthesis was completed in emulsion in one step, yielding 5- to 20-pm microspheres. These microspheres were found to be biodegradable and released three times more pDNA when incubated with hyaluronidase in PBS (phosphate buffered saline) solution (vs enzyme-free PBS). As in the case of films, DNA release from the microspheres was dependent on the DNA loading. DNA-HA microspheres were not directly used for transfection instead, DNA obtained from release experiments was used in transfection of Chinese hamster ovary (CHO) cells using Lipofectamine. The relative levels of transfection over time had the same trend as DNA release from the DNA-HA microspheres and confirmed that released DNA is bioactive. 

As described above, cancer cells produce or induce other cells to produce hyalurooan. This halo of hyaluronan protects the cells against macrophages or leukocytes and shields them from cytostatics. Several studies have dealt with the addition of hyaluronidase to chemotherapy in order to degrade the hyaluronan coaling and to render the cells more accessible to the cytostatic drugs. 

In this chapter we describe some methods used to determine the kinetics of the action of hyaluronidase. Thble 2 presents a survey of the Michaelis-Menten constants (Km) of the action of hyaluronidase on hyaluronan and chondiootin sulfate obtained using different methods. These assays usually make use of hyaluronan as a substrate for hyaluionidase. Various sources of hyalmonan are employed, but these arbitrates have different physicochemical properties (molecular weight intrinsic viscosity). Payan el al [130] investigated the action of Streptmnyces hyahnonidase on hyaluronan from several sources. 

Stem et aL [149] made use of a hyaluronan-binding protein obtained from the tryptic digestion of the proteoglycan core protein of bovine nasal cartilage to detect hy alumni da sc activities in urine samples from wiles tumor patients. The pathophysiology of this tumor is associated with major alterations in the metabolism of hyaluiouan, and it is thought that urinary hyaluronidase can be used as an additional marker. 

Hyaluronan is very metabolically active, with a half-life of 3 to 5 min in the circulation,less than one day in skin, and even in an inert a tissue as cartilage, the HA turns over with a half-life of 1 to 3 weeks.66,67,184 This catabolic activity is primarily the result of hyaluronidases, endoglycolytic enzymes with a specificity in most cases for the ft 1 1 glycosidic bond. 

Okorukwu, O.N. and Vercruysse, K.P., Effects of ascorbic acid and analogs on the activity of testicular hyaluronidase and hyaluronan lyase on hyaluronan, J. Enzyme Inhib. Med. Chem., 18, 377, 2003. 

The space-filling character of glycosaminoglycans appears to be important in morphogenesis, particularly in the development of the skeleton. During these developmental processes, the presence of hyaluronan appears to facilitate the migration of cells. This effect is stopped by the removal of hyaluronan by hyaluronidase and by its replacement with aggregating proteoglycans. 

Hyaluronidases are divided into three main classes according to their mechanism of action on hyaluronan [5],... 

This type of hyaluronidase randomly hydrolyzes the 1,4-linkages between the N-acetyl p-D-glucosamine and the D-glucuronate residues in hyaluronan. The enzyme is subdivided according to its source. 

Commercial preparations usually contain this type of hyaluronidase. The enzyme is found in testicular tissue of most mammals and is located in the acrosomal cap of spermatozoa [6], Testicular hyaluronidase degrades hyaluronan, chondroitin, chondroitin-4- and -6-sulfate to oligosaccharides, mainly tetrasaccharides [1]. Partial degradation of dermatan sulfate has been described [7]. Testicular hyaluronidase had a broad pH range of activity [5]. 

Bollet et al. [11] demonstrated the presence of hyaluronidase activity in various mammalian tissues. They showed that this type of hyaluronidase differed from the testicular type concerning pH optimum and pH range of activity. Subsequent studies revealed that the enzyme was present in the lysosomal fraction of the tissues [12]. The liver is an especially rich source [13]. Degradation of hyaluronan leads to the same end products as testicular hyaluronidase [11]. Lysosomal hyaluronidase from rat liver degrades chondroitin-4- and -6-sulfate, but not dermatan sulfate, desulfated dermatan sulfate, heparan sulfate, keratan sulfate, or heparin [14], Lysosomal hyaluronidase has an acid pH optimum and a narrow pH range of activity [14]. This difference in pH profile of activity has commonly been used to differentiate between testicular and lysosomal hyaluronidase. A similar acid-active hyaluronidase is present in human serum [15]. 

Animal venoms usually possess hyaluronidase activity [17]. The enzymatic properties, including hyaluronidase, of snake venoms have been extensively studied by Tan et al. [18]. Snake hyaluronidase acts on hyaluronan, chondroitin, and chondroitin-4- and -6-sulfate, producing various oligosaccharides, mainly tetrasaccharides [1]. 

Hyaluronidase from bee venom has about the same substrate specificity as snake hyaluronidase [19]. Venom of social wasps was found to contain high levels of hyaluronidase activity, whereas venom from ants contains low levels of activity [20]. Lizard venom contains a hyaluronidase that acts almost specific on hyaluronan, i.e., it has no activity toward chondroitin-6-sulfate, dermatan sulfate, or heparin and only weak activity toward chondroitin-4-sulfate [21]. 

A hyaluronidase has been purified and characterized from stonefish (Synanceja horrida) venom. It acts specifically on hyaluronan, producing tetra-, hexa-, octa-, and decasaccharides, but does not act on chondroitin sulfate or dermatan sulfate [22,23]. 

This type of enzyme is commonly obtained from bacterial sources like pneumococci, staphylococci, streptococci, Clostridia [29], Flavobacterium, and Proteus vulgaris [30], and has been demonstrated in Treponema pallidum [31]. Bacterial hyaluronidases degrade hyaluronan to a disaccharide containing a A-4,5-unsaturated uronic acid by eliminating 1 mole of water from the uronic acid portion of the repeating unit of hyaluronan [29]. The full mechanism of this type of reaction has been elucidated by Ludowieg et al. [32],... 

Hyaluronidase activity has been demonstrated in streptococcal phages [34] and in infective hookworm (Ancylostoma) larvae [35], The latter has been shown to possess specific activity toward hyaluronan. 

Mammalian oocytes are surrounded by several layers of cells embedded in an extracellular matrix. This matrix has been shown to contain protein and hyaluronan [40]. The fertilizing spermatozoon must pass through it to reach the egg. In 1942 McClean and Rowlands demonstrated the possible role of hyaluronidase in dispersing and digesting the layers surrounding the oocyte [41]. Subsequent studies have shown that hyaluronidase is not essential, but is a helpful tool in assisting the passage of the individual sperm toward the oocyte [40],... 

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