NAP alpha-aminoisobutyric acid (IsoNAP)

J Mol Neurosci. 2014 Jan;52(1):1-9. doi: 10.1007/s12031-013-0103-8.


We set out to identify NAP (davunetide) analogs, providing neuroprotection and reducing tau pathology, specifically addressing protection against protein misfolding. NAP (NAPVSIPQ, intranasal formulation AL-108) is a drug candidate that (1) had a statistically significant impact on two measures, namely digit span and delayed-match-to-sample, tests of verbal recall and visual working memory, respectively, in patient population of mild cognitive impairment [preceding Alzheimer's disease (AD)] and (2) protected functional activities of daily living in schizophrenia patients. Previous preclinical studies have shown that stabilization of NAP by replacement of all L-amino acids by D-amino acids resulted in an active peptide, D-NAP. Other NAP mimetics are now explored. A new NAP analog was designed that included replacement of the proline residues by alpha-aminoisobutyric acid to enhance β-sheet breaker characteristics, thereby reducing protein misfolding. Three lines of investigations were chosen: (1) protection against the AD-associated amyloid β (1-42), Aβ1-42, peptide toxicity in cell cultures; (2) inhibition of AD-associated tau aggregation in vitro; and (3) cognitive protection in a mouse model of deficiencies of the NAP parent protein, activity-dependent neuroprotective protein (ADNP), exhibiting tau pathology and neurodegeneration. NAP alpha-aminoisobutyric acid (IsoNAP) protected neurons against AD-associated Aβ1-42-toxicity, inhibited the aggregation of the tau-derived peptide VQIVYK (important for the aggregation of tau into paired helical filaments, which form the tangles found in AD and related disorders), and protected cognitive functions in a model of ADNP deficiency. With AD being the major tauopathy, novel NAP derivatives that reduce tauopathy and provide neuroprotection as well as cognitive protection are of scientific and clinical interest.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aminoisobutyric Acids / chemistry*
  • Amyloid beta-Peptides / toxicity
  • Animals
  • Astrocytes / drug effects
  • Astrocytes / metabolism
  • Cells, Cultured
  • Cerebral Cortex / cytology
  • Cerebral Cortex / drug effects
  • Cerebral Cortex / physiology
  • Homeodomain Proteins / genetics
  • Homeodomain Proteins / metabolism
  • Maze Learning
  • Mice
  • Nerve Tissue Proteins / genetics
  • Nerve Tissue Proteins / metabolism
  • Neurons / drug effects*
  • Neurons / metabolism
  • Neuroprotective Agents / chemical synthesis
  • Neuroprotective Agents / pharmacology*
  • Oligopeptides / chemical synthesis
  • Oligopeptides / pharmacology*
  • Peptide Fragments / toxicity
  • Rats
  • tau Proteins / genetics
  • tau Proteins / metabolism


  • Adnp protein, mouse
  • Aminoisobutyric Acids
  • Amyloid beta-Peptides
  • Homeodomain Proteins
  • Nerve Tissue Proteins
  • Neuroprotective Agents
  • Oligopeptides
  • Peptide Fragments
  • amyloid beta-protein (1-42)
  • tau Proteins
  • 2-aminoisobutyric acid
  • davunetide