Table 1.

Self-association properties of insulin analogs

Analog	t½ hexamer dissociation	Calculated molecular mass by SECa
	min ± S.D.	kDa
Wildtype	7.7 (± 1.3)	9.7
Lisprob	4.6 (± 0.3)	5.1
OrnB29c	8.2 (± 0.8)	8.2
TrpB26, OrnB29	1.2 (± 0.3) × 103	28.0, 4.0

^a Proteins were made 0.6 mm in a buffer containing ZnCl₂ at a ratio of 2 zinc ions per insulin hexamer and applied to SEC column as described under “Experimental procedures.” Masses were calculated from the plot in Fig. 4B.

^b “Lispro” describes insulin analogs containing Pro^B28 →Lys and Lys^B29 →Pro substitutions. These substitutions impair dimerization (28, 29).

^c Use of Orn simplified trypsin-catalyzed semisynthesis (33).