Understand the source comparison
Side-by-Side Structural Comparison
Amino acids 70 83 67 Molecular weight ~7.6 kDa ~9.1 kDa ~7.4 kDa Structural change None (reference) N-terminal extension + R3 substitution N-terminal truncation (loss of Gly-Pro-Glu) IGFBP affinity High ~1,000x reduced vs native Moderately reduced IGF-1R affin
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This page preserves a source comparison for education. It does not add a rating, recommendation or clinical judgment.
- Amino acids
- 70
- 83
- 67
- Molecular weight
- ~7.6 kDa
- ~9.1 kDa
- ~7.4 kDa
- Structural change
- None (reference)
- N-terminal extension + R3 substitution
- N-terminal truncation (loss of Gly-Pro-Glu)
- IGFBP affinity
- High
- ~1,000x reduced vs native
- Moderately reduced
- IGF-1R affinity
- Slightly reduced
- Higher than native
- IGF-2R (M6PR) binding
- Low
- IR cross-reactivity
- Estimated half-life
- ~10–20 min (free)
- ~20–30 hours
- ~20–30 min