Keratan sulfate: Difference between revisions

Latest revision as of 11:18, 15 February 2025

Keratan Sulfate[edit]

Keratan sulfate is a type of glycosaminoglycan (GAG) that is found in various tissues throughout the body, including the cornea, cartilage, and intervertebral discs. It is one of the several types of sulfated GAGs, which are long unbranched polysaccharides consisting of repeating disaccharide units.

Structure[edit]

Keratan sulfate is composed of repeating disaccharide units of galactose and N-acetylglucosamine, which are sulfated at various positions. The degree of sulfation and the specific pattern of sulfation can vary, leading to different forms of keratan sulfate. This variability in structure can affect its biological function and interaction with other molecules.

Function[edit]

Keratan sulfate plays a crucial role in maintaining the structural integrity and function of various tissues. In the cornea, it contributes to transparency and refractive properties. In cartilage, it is involved in providing resistance to compressive forces, working alongside other components such as chondroitin sulfate and collagen.

Biosynthesis[edit]

The biosynthesis of keratan sulfate involves the sequential addition of sugar residues to a core protein, forming a proteoglycan. This process occurs in the Golgi apparatus and involves several glycosyltransferases and sulfotransferases. The core protein is initially synthesized in the endoplasmic reticulum and then transported to the Golgi apparatus for glycosylation.

Clinical Significance[edit]

Abnormalities in keratan sulfate metabolism can lead to various disorders. For example, Morquio syndrome (Mucopolysaccharidosis IV) is a genetic disorder characterized by the accumulation of keratan sulfate due to a deficiency in the enzyme required for its degradation. This leads to skeletal abnormalities, vision problems, and other systemic issues.

Related Pages[edit]

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-'''Keratan sulfate''' is a [[glycosaminoglycan]] (GAG) found on [[proteoglycans]]. It is abundant in the [[cornea]], [[cartilage]], and [[brain]]. Keratan sulfate is unique among the GAGs in that it does not contain [[uronic acid]] and is not sulfated at the [[C-5 position]] of the [[sugar]] residue.
+== Keratan Sulfate ==
+[[File:Keratan_sulfate.svg|thumb|right|Structure of keratan sulfate]]
+'''Keratan sulfate''' is a type of [[glycosaminoglycan]] (GAG) that is found in various tissues throughout the body, including the [[cornea]], [[cartilage]], and [[intervertebral disc]]s. It is one of the several types of sulfated GAGs, which are long unbranched polysaccharides consisting of repeating disaccharide units.
 == Structure ==
-Keratan sulfate consists of a repeating disaccharide unit of [[galactose]] and [[N-acetylglucosamine]]. The galactose residues can be sulfated at the 6-position and the N-acetylglucosamine residues can be sulfated at the 6-position. The degree of sulfation varies among tissues and species.
+Keratan sulfate is composed of repeating disaccharide units of [[galactose]] and [[N-acetylglucosamine]], which are sulfated at various positions. The degree of sulfation and the specific pattern of sulfation can vary, leading to different forms of keratan sulfate. This variability in structure can affect its biological function and interaction with other molecules.
 == Function ==
-Keratan sulfate plays a crucial role in maintaining the transparency of the cornea. It also contributes to the compressive resistance and elasticity of cartilage. In the brain, keratan sulfate is involved in [[neuronal plasticity]] and [[axon guidance]].
-== Clinical significance ==
+Keratan sulfate plays a crucial role in maintaining the structural integrity and function of various tissues. In the [[cornea]], it contributes to transparency and refractive properties. In [[cartilage]], it is involved in providing resistance to compressive forces, working alongside other components such as [[chondroitin sulfate]] and [[collagen]].
-Defects in the metabolism of keratan sulfate can lead to a variety of [[lysosomal storage diseases]], including [[Morquio syndrome]] and [[Macular corneal dystrophy]]. These diseases are characterized by the accumulation of keratan sulfate in tissues and organs, leading to a range of symptoms such as skeletal abnormalities, corneal clouding, and cognitive impairment.
+== Biosynthesis ==
+The biosynthesis of keratan sulfate involves the sequential addition of sugar residues to a core protein, forming a [[proteoglycan]]. This process occurs in the [[Golgi apparatus]] and involves several glycosyltransferases and sulfotransferases. The core protein is initially synthesized in the [[endoplasmic reticulum]] and then transported to the Golgi apparatus for glycosylation.
+== Clinical Significance ==
+Abnormalities in keratan sulfate metabolism can lead to various disorders. For example, [[Morquio syndrome]] (Mucopolysaccharidosis IV) is a genetic disorder characterized by the accumulation of keratan sulfate due to a deficiency in the enzyme required for its degradation. This leads to skeletal abnormalities, vision problems, and other systemic issues.
+== Related Pages ==
-== See also ==
 * [[Glycosaminoglycan]]
 * [[Proteoglycan]]
+* [[Chondroitin sulfate]]
 * [[Morquio syndrome]]
-* [[Macular corneal dystrophy]]
 [[Category:Glycosaminoglycans]]
-[[Category:Biochemistry]]
-{{biochemistry-stub}}