Fungal Sugar Monomers

Khafizah

Natasya

Jojo

Wani

Shin

Thirah

Muaz

Cell wall of fungi is generally constructed

of 3 layers:

1. α-glucan layer – a glucan is a polymer of

glucose

2. ß-glucan layer

3. Outer layer of glycoprotein

In addition, chitin may be a significant component of certain cell wall structures.

Generally composed of the α (1-3)

glucan polymer.

However, α (1-4) glycosides are variably

present.

Α-glucan material appears as a fibrillar

layer adjacent to the plasma membrane

and is thought to serve a largely

structural role, stiffening the basal layer

of the cell wall.

α-glucan layer does not occur in

Saccharomyces.

Among ascomycetes, the α-glucan is

found in Schizosaccharomyces, but is

not known from any other yeasts.

α-glucans also form a significant,

sometimes even dominant, part of the

cell wall in many basidiomycetes.

The bulk material of cell wall is usually in the form of ß (1-3) glucan.

This forms a very stable hydrogen-bonded tripe, helix in solution.

The packing of these triple helix structures appears to be controlled by the size and frequency of very short (1-6) side chains, sometimes consisting of only a single glucose monomer.

In addition to ß (1-3) glucan, cell wall contains ß (1-6) glucan.

This is not simply a ß (1-3) glucan with big side chains, but a polysaccharide with a true ß (1-6) backbone.

It is strongly involved in cross linking the various components of the cell wall.

The outermost layer of the cell wall oscomposed of diverse proteins bearing polysaccharide side chains composed of mannose..

These are attached through their mannan side chains via (1-3) linkage with ß (1-6) glucan.

Real life appears to be very much complex, involving different interactions between glycoproteins and bulk cell wall materials.

In many systems chitin is a major

constituent of the cell wall.

In others, it is involved only in cell division

or reproductive structures and is virtually

absent otherwise.

Glucomannan is a water-soluble polysaccharide.

As a dietary fiber, it possesses several potential health

benefits, which include treatment of constipation, decline in

total cholesterol and low-density lipoprotein, increase of

insulin sensitivity, weight loss and also wound healing.

Fenugreek galactomannans is used as food emulsifiers.

The detection of galactomannan at concentrations as low

as 1 ng/ml can

be useful for the early initiation of antifungal therapy and

monitoring

treatment in clinically documented lung aspergillosis.

http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3531

755/http://iai.asm.org/content/62/12/5424.abstr

acthttp://www.sciencedirect.com/science/article/

pii/S0023643896901796

http://journals.lww.com/pidj/Abstract/1996/030

00/Prospective_sandwich_enzyme_linked_immu

nosorbent.11.aspx

Biarritz, France. March 10-14, 2007. Cell Wall

Polysaccharide of Fungi and plants