Biomedical Engineering Reference
In-Depth Information
TABL E 4.6. Characterization After Deamidation in pH 8.5 Buffer
Identified Sites of Deamidation
Characterization
Native IEF
Band 1/Band 2
OD Ratio
F Protein
Binding
ELISA (%)
a
F Protein
Binding Kinetics
(SPR) (k
off
)(s
1
)
b
Asn-289
(%)
Asn-318
(%)
Asn-387
(%)
Total
Deamidation (%)
RSV
Microneutralization
Samples
0
3.9
14.0
17.9
3.4
3.71
10
6
Initial
1.4
4.9
12.3
18.6
2.3
105
Neutralizes RSV
4.66
10
6
1 week
2.1
4.8
27.1
34.0
1.4
103
Neutralizes RSV
4.31
10
6
2 weeks
2.1
6.5
35.5
44.1
1
107
Neutralizes RSV
10
6
3 weeks
2.7
5.7
46.6
55.0
0.71
90
Neutralizes RSV
4.55
10
6
4 weeks
3.8
4.8
53.2
61.8
0.71
101
Neutralizes RSV
4.55
4.93
10
6
5 weeks
3.4
5.8
55.9
65.1
0.5
100
Neutralizes RSV
Note: 0, 3.9, 14.0, and 17.9 are reference standards.
a
Value listed is % binding relative to reference standard.
b
Samples extracted from human plasma had low total protein concentrations. Because the SPR off-rate is independent of protein concentration, it was used to analyze these
samples.
