A feature of glycans that explains many of their biological actions is that they bind specifically to proteins and other glycans. One reflection of this is their ability to bind some viruses, bacteria, and parasites.

Influenza virus A binds to cell surface glycoprotein receptor molecules containing N-acetylneuraminic acid via a hemagglutinin protein. The virus also has a neuraminidase that plays a key role in allowing elution of newly synthesized progeny from infected cells. If this process is inhibited, spread of these viruses is markedly diminished. Inhibitors of this enzyme (eg, zanamivir, oseltamivir) are now available for use in treating patients with influenza. Influenza viruses are classified according to the type of hemagglutinin (H) and neuraminidase (N) that they possess. There are at least 16 types of hemagglutinin and 9 types of neuraminidase. Thus, avian influenza virus is classified as H5N1.

Human immunodeficiency virus type 1 (HIV-1), the cause of AIDS, attaches to cells via one of the surface glycoproteins gp 120 and uses another surface glycoprotein (gp 41) to fuse with the host cell membrane. Antibodies to gp 120 develop during infection by HIV-1, and there has been interest in using the isolated protein as a vaccine. One major problem with this approach is that the structure of gp 120 can change relatively rapidly due to mutations, allowing the virus to escape from the neutralizing activity of antibodies directed against it.

Helicobacter pylori is the major cause of peptic ulcers. It binds to at least two different glycans present on the surfaces of epithelial cells in the stomach allowing it to establish a stable attachment site to the stomach lining. Similarly, many bacteria that cause diarrheaattach to surface cells of the intestinal mucosa via glycans present in glycoproteins or glycolipids. The attachment of the malarial parasite Plasmodium falciparum to human cells is mediated by a GPI present on the surface of the parasite.

اخر الاخبار

اخبار العتبة العباسية المقدسة

قسم الشؤون الطبية يقدم الخدمات الصحية والعلاجية لزائري مدينة سامراء

العتبة العباسية المقدسة تقدم خدماتها لزائري مرقد الإمامين العسكريين (عليهما السلام) في سامراء

المجمَع العلمي ووفد وزارة التربية يبحثان سبل التعاون المشترك

قسم الشؤون الفكرية يصدر العدد 192 من مجلة الرياحين للأطفال

المزيد

الآخبار الصحية

كنز غذائي على طبقك.. ماذا تفعل السبانخ بجسمك؟

ما لا يتوقعه أحد.. "سر غذائي" في الجبن الدسم

لتحسين الهضم والنوم.. هذا أفضل وقت لتناول العشاء

10 طرق بسيطة وغير مألوفة لحرق المزيد من السعرات يوميا

المزيد

الآخبار التكنلوجية

سابقة بعالم الطيران.. طائرة تقرر الهبوط بنفسها بعد ظرف طارئ

"الإنفلونزا الخارقة" تكتسح دول العالم.. وتثير قلقا كبيرا

مرحلة ما قبل الأعراض.. دواء جديد يستهدف "شرارة" الزهايمر

إزالة ثاني أكسيد الكربون من الغلاف الجوي.. ما دور المحيطات والبحار؟

المزيد

مواضيع ذات صلة

Isoforms of Cytochrome P450 Hydroxylate a Wide Variety of Xenobiotics in Phase 1 Metabolism

Glycoproteins are Involved in Many Biological Processes & in Many Diseases

The Biosynthesis of N-Linked Glycoproteins Involves Dolichol-P-P-Oligosaccharide

Glycoproteins Contain Several Types of O-Glycosidic Linkages

There are Three major classes of Glycoproteins

Biochemical Markers of Bone Remodeling in Postmenopausal Osteoporosis

Biochemical Markers of Bone Remodeling in Different Clinical Conditions Affecting Bone Tissue Metabolism

Free Radicals & Antioxidant Nutrients

Vitamin B12 is Found only in Foods of Animal Origin

Vitamin B6 is important in Amino Acid & Glycogen Metabolism & in Steroid Hormone Action

Niacin is not Strictly A Vitamin

Bone Tissue Biochemistry