Figure 1.

Characterization of the Protein Nanocluster

(A) Mechanism illustration of the interactions between proteins and PBA-polycations.

(B) Particle sizes and zeta potentials of naked BSA, pDET/BSA, PAD/BSA, PCD/BSA, and FPCD/BSA with series PBA modification ratios, where the number 1 means low DS polymer, 2 means moderate, and 3 means high DS polymer (n = 3, mean ± SD).

(C) Chemical structures of the polymers, size distribution, and morphology observation of pDET/BSA, PAD/BSA, PCD/BSA, and FPCD/BSA nanoclusters (PAD3, PCD3, and FPCD3 were chosen as the representative polymers).

(D) Fluorescence spectrum of BSA-FITC solution with increasing PCD added.

(E) Circular dichroism spectrum of BSA and PCD/BSA.

(F) Relative fluorescence intensity of BSA-FITC, PCD/BSA-FITC, and PCD/BSA-FITC treated with Triton X-100, Tween 20, or heparin (n = 3, mean ± SD). ∗p < 0.05, ∗∗p < 0.01.

See also Table S1 and Figure S1–S7.