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Degradation Processes

Light Scattering and Degradation

light scattering and degredation

From analysis of Mass/Time curve, discover:

  • does degradation occur?
  • absolute scission rate
  • polymer structure
  • enzyme action
  • degradation mechanism (random, endwise, multiple phases)

Examples of degradation process studied:

A. Signatures for time dependent light scattering enzymatic degradation of linear molecules

Signatures for time dependent light scattering enzymatic degradation of linear molecules

Signatures for time dependent light scattering enzymatic degradation of linear molecules

B. New signatures for time-dependent light scattering degradation of branched polymers

C. Proteoglycan monomers & aggregates

Proteoglycan monomers & aggregates

Proteoglycan monomers & aggregates

D. Enzymatic Degradation monitored by SMSLS - Hyaluronate degradation by hyaluronidase

IR/Kc signatures for different concentrations of hyaluronidase used

IR/Kc signatures for different concentrations of hyaluronidase used (M. Drenski, W. F. Reed, J. App. Polym. Sci. 2002 , 92, 2724)

E. Enzymatic degradation monitored by TDSLS.
Enzymatic hydrolysis was monitored in real-time using time dependent static light scattering (TDSLS) for a variety of galactomannans to determine kinetic parameters, investigate enzyme mechanisms, and make deductions concerning the sequentiality of side-chain substitution (J. L. M. S. Ganter; J. C. Sabbi; W. F. Reed,Biopolymers 2001, 59, 226–242).

LS 90° for enzymatic hydrolysis of Mimosa scabrella (Ms) by a-galactosidase. Inset shows LS 90° for enzymatic hydrolysis of Ms by b-mannanase. Also shown is hydrolysis for a b-mannanase./a-galactosidase.

Mw,ap and Rg for Moldenhawera floribunda (Mf) and Melanoxylon brauna (Mb), respectively, during the enzymatic hydrolysis with a-galactosidase. In the inset: Mw,ap and Rg of Ms during the enzymatic hydrolysis with b-mannanase.

Top: LS 90° for enzymatic hydrolysis of Mimosa scabrella (Ms) by a-galactosidase. Inset shows LS 90° for enzymatic hydrolysis of Ms by b-mannanase. Also shown is hydrolysis for a b-mannanase./a-galactosidase.  Bottom: Mw,ap and Rg for Moldenhawera floribunda (Mf) and Melanoxylon brauna (Mb), respectively, during the enzymatic hydrolysis with a-galactosidase. In the inset: Mw,ap and Rg of Ms during the enzymatic hydrolysis with b-mannanase.

 

F. Enzymatic degradation monitored by SEC
Effects of enzymes on galactomannans samples: raw data and mass distribution (J. L. M. S. Ganter; J. C. Sabbi; W. F. Reed,Biopolymers 2001, 59, 226–242).

(a) Raw SEC chromatograms of Mimosa scabrella (Ms), before enzymatic hydrolysis, after separate enzymatic hydrolysis by b-mannanase and a-galactosidase, and after combined hydrolysis by b-mannanase/a-galactosidase at 25°C. (b) Raw SEC chromatograms of Ms, Moldenhawera floribunda (Mf), and Melanoxylon brauna (Mb) before and after enzymatic hydrolysis by b-mannanase at 25°C.

Mass distribution of Mb, before and after enzymatic hydrolysis by a-galactosidase

Top: (a) Raw SEC chromatograms of Mimosa scabrella (Ms), before enzymatic hydrolysis, after separate enzymatic hydrolysis by b-mannanase and a-galactosidase, and after combined hydrolysis by b-mannanase/a-galactosidase at 25°C. (b) Raw SEC chromatograms of Ms, Moldenhawera floribunda (Mf), and Melanoxylon brauna (Mb) before and after enzymatic hydrolysis by b-mannanase at 25°C. Bottom: Mass distribution of Mb, before and after enzymatic hydrolysis by a-galactosidase