Degradation of standard proteins and peptides

The oxidized B-chain of insulin has served for over 30 years as the substrate of choice for the initial screening of the specificity of a newly discovered protease. The sequence, given in Table 4, contains a selection of peptide bonds 'on offer' to a proteolytic enzyme, and almost certainly has an unfolded structure so that all peptide bonds are freely accessible.

Table 4 Insulin B-chain, oxidized: cleavage points with several proteases

Sequence

F V N Q H L C* G 5 H L V E A L Y L V C* G E K C

JFFYTP2CA

Porcine pepsin

t I I

Trypsin

t

ElasL.ase

*

*

Papain

C * -"1

: i

Cathepsin B

: : : i :

Subtilisin

- ^ j *

Mcprin

: : ; t : t t :

* "

References: pepsin: (64-66), trypsin. (57). eiastase, (68), papain. (69), cathepsin 8, ¡70,71), subtiiisin, ;72), meprm. (73)

References: pepsin: (64-66), trypsin. (57). eiastase, (68), papain. (69), cathepsin 8, ¡70,71), subtiiisin, ;72), meprm. (73)

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Diabetes 2

Diabetes 2

Diabetes is a disease that affects the way your body uses food. Normally, your body converts sugars, starches and other foods into a form of sugar called glucose. Your body uses glucose for fuel. The cells receive the glucose through the bloodstream. They then use insulin a hormone made by the pancreas to absorb the glucose, convert it into energy, and either use it or store it for later use. Learn more...

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