STRC N-Glycosylation Analysis

Key Finding

Truncation at residue 700 removes 9 of 14 N-glycosylation sites, but all 5 retained sites are confidently predicted functional by NetNGlyc 1.0. Average retained score (0.66) is comparable to full protein average (0.63).

Retained Sites (mini-STRC 700-1775)

Full positionSequonScoreJuryNotes
N824NDSV0.5255/9Borderline but above threshold
N916NQSV0.7078/9Strong
N964NGTL0.6648/9Strong
N1179NLTL0.7198/9Strongest retained site
N1274NESI0.5676/9Moderate

Lost Sites (N-terminal 1-699)

9 sites removed. Notable: N696 NPSS (0.577) sits in the disorder zone (IUPred3 0.82 at res 691) with a PRO-X1 warning, suggesting poor glycosylation efficiency even in full protein.

Implications

  1. Mini-STRC retains 36% of glycosylation sites (5/14)
  2. All retained sites are high-confidence (no marginal calls)
  3. IgK signal peptide doesn’t affect glycosylation prediction (scores within 0.003)
  4. Lost sites are mostly in disordered N-terminal (may not be efficiently glycosylated in vivo anyway)
  5. Whether 5 vs 14 glycans matters for STRC function is an experimental question

Connections