Table 1.

A decade of racemic protein crystallography (at the time of writing).

Protein	Function	Length[a]	Res. [Å]	Space group	PDB accession	Structural insights	Ref.
Lacticin Q	Bacteriocin	53	0.96	P1	7P5R	First reported crystal structure	[31]
CyO2	Bracelet cyclotide	30	1.17	P1211	7RMQ	First reported crystal structures of bracelet cyclotides	[32]
CyO2 (I11L)			1.04	P1211	7RMR
CyO2 (I11G)			1.10	P1211	7RMS
Hyen D			1.35	P1211	7RIH
Hyen D (I11L)			1.22	P $\bar{1}$	7RII
Hyen D (I11G)			1.30	P1	7RIJ
Calcicludine	Kunitz‐type serine protease inhibitor homolog	60	2.52	I41	6KZF	Confirmation of novel disulfide surrogate bridge strategy (DADA)	[33]
rC5a‐desArg	Rat anaphylatoxin	76	1.80	P1	[g]	New insights on C‐terminal conformation	[34]
Chimeric‐rC5a		77	1.31	P212121	g	Chimeric protein probes conjugated to small‐molecule antagonist	[35]
rC5a			1.58	P $\bar{1}$	g
M2‐TM[b]	Ion channel TM helix	24	2.00	P21 /c	4RWB	Investigations of a heterochiral coiled coil	[27b]
M2‐TM[c]			1.05	P $\bar{1}$	4RWC
M2‐TM (I39A)[c]			1.55	P $\bar{1}$	6MPL		[27a]
M2‐TM (I42A)[c]			1.40	P $\bar{1}$	6MPM
M2‐TM (I42E)[c]			1.40	P $\bar{1}$	6MPN
Melittin	Honeybee venom	27	1.27	C2	6O4M	Retention of native quaternary structure	[36]
Ribifolin	Orbitides from Jatropha	8	0.99	P121/n1	6DKZ	Unveil structures of Jatropha orbitides	[37]
Pohlianin C		8	1.20	Pcab	6LD0
Jatrophidin		8	1.03	P121/n1	6DL1
GsMTx4	Spider venom	34	1.75	P $\bar{3}$	g	First reported crystal structure	[38]
BTD‐2	Baboon θ‐defensin	18	1.45	P $\bar{1}$	5INZ	Novel oligomeric state resembles mechanistically relevant assembly	[39]
Snakin‐1	Potato snakin	63	1.50	P1	5E5Y	Novel use of radiation damage induced phasing of quasi‐racemic crystals	[40]
			1.60	P21/c	5E5Q
			1.57	P21/c	5E5T
Ubiquitin	Ubiquitin	76	1.95	[d]	[g]	Confirm folding of synthetic protein	[41]
M1‐linked tri‐Ubs		76[e]	1.80	P1	5GO7	D‐monomeric Ub can facilitate Ub oligomer crystallization	[28]
M1‐linked tetra‐Ub			2.18	P21	5GO8
K6‐linked di‐Ub			1.15	P1	5GOB
K11‐linked di‐Ub			1.73	P1	5GOC
K27‐linked di‐Ub			1.15	P1	5GOD
K29‐linked di‐Ub			1.98	P2	5GOG
K33‐linked di‐Ub			1.95	P1	5GOH
K48‐linked di‐Ub			1.59	P1	5GOI
K63‐linked di‐Ub			1.55	P21212	5GOJ
K11/K63‐linked tri‐Ub			1.84	P22121	5GOK
K27‐linked di‐Ub		152	1.55	C2	5J8P	Largest true synthetic racemic proteins to be crystallized	[42]
K27‐linked tri‐Ub		228	2.10	H3	5JBV
VHP	Vinillin headpiece domain	35	2.10	P $\bar{1}$	3TRW	Investigation of pentafluoro phenylalanine (F5Phe) amino acids on protein structure	[43]
VHP			2.30	I‐4c2	3TRY
VHP (F5Phe10)			1.46	F222	3TJW
VHP (F5Phe17)			1.00	P1	3TRV
VHP (β3‐hGln26)			1.30	P1	5I1N	Investigation of beta amino acids on protein structure	[44]
VHP (ACPC26)			1.35	P1	5I1O
VHP (β3‐hLys30)			1.40	P1	[g]
VHP (APC30)			1.12	P1	5I1S
Ts3	Scorpion venom	64	1.93	P $\bar{1}$	5CY0	First reported structure of Ts3	[45]
Magainin 2 (L‐1)	Amphibian HDP	23	1.75	I‐42d	4MGP	Beta amino acid variants investigating phenylalanine zipper motif	[46]
Magainin 2 (L‐2)			2.20	P21212	5CGN		[47]
Magainin 2 (L‐3)			1.50	P1	5CGO
ShK	Sea anemone venom	35	0.97	P121/c	4LFS	Structure variation to NMR and enantiospecific activity	[48]
ShK analogue			1.20	H‐3	4Z7P	Structure activity relationships	[49]
ShK (allo‐Thr13)			0.90	P1	5I5B	Investigation of side chain chirality on protein structure	[50]
ShK (allo‐Thr31)			1.30	P1211	5I5C
ShK (allo‐Ile7)			1.20	C2	5I5A
Rv1738	M. tuberculosis protein	94	1.50	C12/c1	4WPY	First reported structure, unknown function	[51]
STFI‐1	Sunflower trypsin inhibitor	14	1.25	P $\bar{3}$	4TTK	Disulfide‐rich scaffolds for drug design	[52]
cVc1.1	Cone snail venom	22	1.70	Pbca	4TTL
kB1	Plant cyclotide	29	1.90	P $\bar{1}$	4TTM
kB1 (G6A)			1.25	P $\bar{1}$	4TTN
kB1(V25A)			2.30	P $\bar{1}$	4TTO
Ser‐CCL1	Chemokine	73	2.15	P1	4OIJ	Crystal structure of a homogenous, glycosylated chemokine	[53]
Glycosylated Ser‐CCL1		73[f]	2.10	P1	4OIK
DKP Ester Insulin	Synthetic hormone+derivatives	51	1.60	P $\bar{1}$	4IUZ	Confirm folding of synthetic derivative	[54]
Ester insulin			1.50	I213	5EN9	Confirmation of correctly folded synthetic protein for isotope experiments	[55]
Human insulin			1.35	I213	5ENA
VEGF‐A/antagonist complex	Vascular endothelial growth factor A+D‐protein binder	102+56	1.60	P21/n	4GLN	First reported structure of a heterochiral protein complex by racemic crystallography	[56]
Crambin analogue	Thionin protein	46	1.08	P1211	3UE7	Novel linear‐loop peptide chain topology	[29a]
Kaliotoxin	Scorpion venom	38	0.95	P $\bar{1}$	3ODV	Basis for structure activity relationships	[57]
Omwaprin	Snake venom	50	1.30	P21/c	3NGG	First reported structure	[30]

[a] Total amino acid length of synthetic protein enantiomer. [b] Crystallized from monoolein lipidic cubic phase. [c] Crystallized from racemic lipids. [d] Data unavailable. [e] Residues in D‐protein enantiomer. [f] 73 residues+oligosaccharide. [g] Not reported/deposited.