TABLE 1.

Stability of sciatic nerve myelin in a sealed capillary

− indicates dimensions absent because of insufficient resolution of the x-ray pattern (see “Experimental Procedures”).

Timea	Dimensionsb				Δ/dc	Myelind	M/(M+B)e
	d	cyt	lpg	ext
	Å					%
WT
10 min	175.0	31	48	48	0.023		0.35
7 h	174.8	31	49	46	0.017		0.35
S63C(+/+)
10 min	174.3	31	47	49	0.029		0.17
7 h	173.1	32	46	49	0.029	95	0.15
	∼219	−	−	−		5
S63C(+/−)
10 min	174.9	31	48	49	0.029	92	0.21
	∼210	−	−	−		8
7 h	173.2	−	−	−	0.023	59	0.21
	204.7	−	−	−		41
S63C(−/−)
10 min	210.7	33	49	80	0.057		0.13
7 h	207.0	31	50	76	0.048		0.11
P0(+/−)
10 min	180.1	30	50	50	0.028		0.28
7 h	180.2	31	49	51	0.022	45	0.36
	197.7	−	−	−		55
P0(−/−)
10 min	187.3	−	−	−	0.048		0.06
7 h	187.0	33	46	62	0.043		0.04

^a Myelin structure was assessed by XRD immediately after dissection and 7 h later.

^b The abbreviations used are as follows: d, myelin period, as measured from the diffraction spectra; cyt, cytoplasmic apposition; lpg, separation between lipid polar head group layers; ext, extracellular apposition; all as determined from the membrane density profiles (see “Experimental Procedures” for details).

^c The irregularity in the packing of myelin membranes was determined from the breadths of the x-ray reflections (15) and expressed as a fraction of the periodicity d.

^d The percentage of the total myelin that is in the swollen state, calculated from P_i = Σ_h (hI_i(h)/d_i²) (50), where I(h) is the integrated intensity of the peak corresponding to the hth Bragg order, and d is periodicity.

^e Relative amount of compact myelin M/(M+B) (see “Experimental Procedures”).