Table 1. Molecular mass of Hua -Syn species from Ciphergen SELDI-TOF MS analysis
|
Hua -Syn Species (source) |
Predicted molecular mass, Da (∆Da from FL) |
Observed molecular mass, Da (∆Da from FL) |
SEM (n) |
|
Syn140 (COS1) |
14460.16 |
14,538.60 |
3.70 (3) |
|
Syn130 (COS1) |
13,277.90 (1,182.26) |
13,356.53 (1,182.07) |
0.23 (3) |
|
Syn124 (COS1) |
12,541.20 (1,918.96) |
12,620.78 (1,917.82) |
1.39 (4) |
|
Syn123 (COS1) |
12,470.12 (1,990.04) |
12,544.99 (1,993.61) |
1.79 (8) |
|
Syn122 (COS1) |
12,341.00 (2,119.16) |
12,406.43 (2,132.17) |
2.21 (4) |
|
Syn120 (COS1) |
12,111.81 (2,348.35) |
12,184.74 (2,353.86) |
3.46 (8) |
|
SynFL (Human) |
14,460.16 |
14,540.17 |
4.95 (15) |
|
Syn12 (Human) |
12,470.12 (1,990.04) |
12,549.69 (1,990.48) |
4.46 (15) |
|
SynFL (AT Tg) |
14,490.19 |
14,552.56 |
3.43 (8) |
|
Syn12 (AT Tg) |
12,500.15 (1,990.04) |
12,559.44 (1,993.12) |
3.52 (8) |
The average masses (Da) of immunoprecipitated Hua -Syn species were determined from multiple, independent Ciphergen SELDI-TOF MS analyses. The average masses of a -Syn species from human brain were determined from a -Syn immunoprecipitated from four individuals. The average masses of a -Syn species from A53T transgenic mice (AT Tg) were determined from multiple immunoprecipitations from two mice. The number of determinations (n) are shown. The apparent masses of a -Syn species are 80–60 Da higher than those predicted from the amino acid sequences. The Ala ® Thr substitution contributes to the slightly higher mass of Hua -Syn from Tg mice. Because the mass differences between a -SynFL and a -Syn∆C (∆Da) is consistent with those predicted from the amino acid sequences, the source of increased mass is not within the region removed in a -Syn12. The apparent mass of a -Syn12 and the differences in mass between a -SynFL and a -Syn12 is only consistent with a -Syn12 missing the C-terminal 17 amino acids.