Table 6.

Summary of block chemistries, synthesis and properties of protein-based block copolymers.

Origin		A Block	B Block	Synthesis	Mw, kDa	Morphologies	Secondary Structure	Solvent	Techniques	Size	Applications	References
Silk-based
	1	silkworm silk block: [(GAGAGS)9]12	Cell attachment domain of human fibronectin	Genetic Engineering	95	woven sheaves microstructures	crystalline β-sheets	formic acid (88 %)	WAXS, TEM, SAED	W= 12 ± 2 nm	tissue engineering and regenerative medicine	Anderson et al., 1994
			[GAAVTGRGDSPASAAGY]12
	2	silk-like block I: [(GA)3GE]28	silk-like block II: [(GA)3GL]28	Genetic Engineering	32	fibrils	stacks of β-sheets, β-turns	formic acid (70 %)	FTIR, CD, tensiometry, AFM	H = 1.5 - 7.5 nm; W = 20 - 30 nm	biomedical applications	Werten et al., 2008
		silk-like block I: [(GA)3GE]24	silk-like block II: [(GA)3GE]24	Genetic Engineering	28	fibrils	β-sheets and β-turns	formic acid (70 %)	FTIR, CD, tensiometry, AFM	H = 1.5 - 7.5 nm; W = 20 - 30 nm	biomedical applications	Werten et al., 2008
	3	spider silk block from A. diadematus: (AEAEAKAK)2	spider silk block from A. diadematus: (GPGQQ)6	Genetic Engineering	44	fibril network	antiparallel β-sheets and β-turns	aqueous solution	HRSEM, FTIR, CD, NMR	D = 10 - 20 nm	tissue engineering	Qu et al., 2000
		spider silk block from N. clavipes: (SGRGGLGGQGAGAAAAAGGAGQGGYGGLGSQGT)6	(K)15,30,45	Genetic Engineering	23, 25, and 27	films	β-sheets	HFIP/water	DLS, AFM, cell viability assay		gene delivery	Numata et al., 2009
	4	hydrophobic block from N. clavipes dragline silk: (GAGAAAAAGGAG)1-6	hydrophilic block from N. clavipes dragline silk: QGGYGGLGSQGSGRGGLGGQ	Genetic Engineering	8 - 13	nanofibers, bowl-shapwed micelles, polymerosomes	antiparallel β-sheets	aqueous solution	FTIR, AFM, SEM	D1 = 1-3 μm; D2 = 70μm; W= 400 nm	controlled drug delivery, tissue engineering, and biosurface engineering	Rabotyagova et al., 2009
Silk-Elastin
	1	[GAGAGS]11	[GXGVP)9]11	Genetic Engineering	47	hydrogels	N/A	PBS	microrheology	N/A	drug delivery	Nagarsekar et al., 2002
	2	[(GAGAGS)4]12(GAGAGS)	[(GXGVP)8]13	Genetic Engineering	70	hydrogels	N/A	aqueous solution	turbidity assay, DNA release study	N/A	controlled gene delivery system	Megeed et al., 2002
	3	GAGAGS	GVGVP	Genetic Engineering	55 - 87	hydrogels	N/A	PBS	microrheology, DSC	N/A	controlled gene delivery system	Haider et al., 2005
Others
	1	spider silk block: GGAGQGGYGGLGGQGAGRGGLGGQGAGAAAA	Collagen block: (GXY)r	Genetic Engineering	57 - 60	fibers* (ongoing study)	N/A	N/A	N/A	N/A	biomedical applications	Teule et al., 2003
	2	(KHKHKHKHKK)6	FGF2 represents human fibroblast growth factor 2	Genetic Engineering	27	microparticles	N/A	PBS	cell proliferation assay, cell toxicity assays, photon correlation spectroscopy (PCS)	D = 230; 500; 800 nm*	non-viral gene delivery	Hatefi et al., 2006
	3	coiled-coil block: (ISSLESK)-(IYYLEYK)2-(ISSLESK)	random coil: [(AG)3PEG]10	Genetic Engineering	14 - 20	hydrogels	α-helical coiled-coil	PBS	CD, AUC, SEM, microrheology	N/A	drug delivery systems	Xu and Kopecek, 2008
		COMP block: DLAPQMLRELQETNAALQDVRELLRQQVKEITFLKNTVMESDASG	elastin block: [(VPGVG)2VPGFG(VPGVG)2]5	Genetic Engineering	22, 23, and 35	aggregates	random coils or β-spirals	PBS	far-UV CD, DLS, SALS	Rh = 60-80 nm	“smart” biomaterials	Haghapanah et al., 2009
	4	leucine zipper block: LGHELAEHKKKLAQLKSELAALKKELAEWE	random coil block: (GAGAGAGPE)10	Genetic Engineering	18	hydrogels	disorderd central domain, helical conformation of the end blocks	PBS	CD, confocal microscopy, surface absorption and cell response assays	N/A	cell-cpecific surface coatings	Fischer et al., 2007
	5	(APQMLRELQETNAALQDVRELLRQQVKEITFLKNTVMESDAS) and coiled-coil leucine zipper block (SGDLENEVAQLEREVRSLEDEAAELEQKVSRLKNEIEDLKAE)	(AGAGAGPEG)10	Genetic Engineering	20 - 22	hydrogels	α-helical coiled-coil	aqueous solution	DLS, microrheology	N/A	tissue engineering materials	Shen et al., 2006