Comparisons
Follistatin 315 vs 344: Isoforms and Heparin Binding
Follistatin isoforms differ at the C-terminus, which changes heparan sulfate binding and where the protein stays. What that means in the laboratory.
Peptide chemistry
What is physically in the vial, and the chemistry that decides it. These articles cover sequence and three-letter notation, salt form and counterion and why they move the weight on the label, how molecular weight relates to net peptide content, solubility and the solvents it depends on, and the synthesis and purification steps that leave the impurities a certificate later reports.
Testing & Quality
Peptide Counterions: TFA vs Acetate and Why It Matters
Every basic peptide arrives as a salt. Why trifluoroacetate is the default, what exchange achieves, and how the counterion distorts concentration.
Comparisons
Is NAD+ a Peptide or a Coenzyme?
NAD+ is a dinucleotide coenzyme, not a peptide. Why it appears in peptide catalogues anyway, and what that means for how it is handled.
Research Reviews
Dihexa Acetate: Structure, Salt Form and Naming
Dihexa is a modified angiotensin IV tripeptide carrying two hexanoyl groups. What the acetate salt means and why the mass must be checked.
Comparisons
NAD+ to NADH: Reduction or Oxidation?
NAD+ to NADH is a reduction. Why the plus sign is not a charge on the whole molecule, and why the ratio matters more than either concentration.
Testing & Quality
Custom Peptide Synthesis: What to Specify
A custom peptide order is a specification, not a request. Which parameters to state, which sequences are difficult, and what the quotation leaves out.