PI Mtoyoura: a new PI M subtype found by separator and hybrid isoelectric focusing.
In the course of a population study of alpha 1-antitrypsin polymorphism by separator isoelectric focusing, a variant phenotype having a somewhat narrower spacing than PI M1M3 was observed in a Japanese blood donor. Family studies by hybrid isoelectric focusing in a carrier ampholyte-supplemented immobilized pH gradient from 4.35-4.65 revealed that the products of the responsible gene, PI*Mtoyoura, were extremely close but slightly cathodal to those of PI*M1. The difference in isoelectric point between them corresponded to the resolving limit of isoelectric focusing. For this reason, although the propositus' father was deduced to have the genotype PI*M1/PI*Mtoyoura, the products of these two genes failed to form a double band pattern. Thus, the gene frequency for PI*Mtoyoura was unknown. These findings, however, indicate that a further microheterogeneity in the PI M subtype exists at least in the Japanese.
Yuasa
I
I
Department of Legal Medicine, Tottori University School of Medicine, Yonago, Japan.
Suenaga
K
K
Umetsu
K
K
Inagaki
O
O
Ikebuchi
J
J
Ito
K
K
Okada
K
K
D005260:Female; D006801:Humans; D007525:Isoelectric Focusing; D007564:Japan; D008297:Male; D010375:Pedigree; D010641:Phenotype; D011480:Protease Inhibitors / Q000235:genetics / Q000302:isolation & purification*
D011480:Protease Inhibitors