Familial lecithin-cholesterol acyltransferase deficiency in four Norwegian Families. Evidence for low levels of a functionally defective enzyme.
Familial lecithin-cholesterol acyltransferase deficiency in four Norwegian Families. Evidence for low levels of a functionally defective enzyme.
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四个挪威家庭存在家族性卵磷脂胆固醇酰基转移酶缺乏症。
DOI：
10.1111/j.0954-6820.1981.tb09849.x
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发表时间：
1981
影响因子：
--
通讯作者：
Torsvik,H
中科院分区：
文献类型：
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作者：
Albers,JJ;Gjone,E;Adolphson,JL;Chen,CH;Teisberg,P;Torsvik,H
通过放射免疫测定法测定了4个LCATase缺乏症挪威家族的LCAT-胆固醇酰基转移酶（LCATase）质量。通过Glomset‐Wright法（G‐W法）和斯托克‐Norum放射性测定技术（S‐N法）测量了一些家族成员的LCAT酶活性。还使用含脱辅基蛋白A-I的蛋白脂质体，通过敏感的常见合成底物方法在其中一个家族中进行了测定。10个专性杂合子的LCATase水平为3.4±0.5 μg/ml（范围2.8-4.0），约为同时采样的8个对照受试者平均值（5.0±0.7 μg/ml，范围4.2-5.8）的55-80%。根据LCAT酶缺陷基因与α-触珠蛋白基因的连锁推断的6个假定杂合子的LCAT酶水平为3.2±0.6，约为对照值的50-80%。8例LCATase缺乏症受试者的LCATase质量为1.0±0.2 μg/ml（范围0.5-1.3），约为对照水平的10-25%。通过合成底物法测定酶活性的单个LCATase缺陷受试者的LCATase活性为3.6 nmol/（ml·h），不到正常受试者活性水平100 nmol/（ml·h）的4%，而三个专性杂合子的LCATase活性为48、54和64 nmol/（ml·h），约为正常水平的50-60%。通过G-W方法（平均值64，范围55-77 nmol/（ml·h），n= 6）或通过S-N方法（平均值44，范围34-67，n= 11）在杂合子中测量的LCAT酶活性显著低于30例对照受试者（G-W方法：平均值120，范围91-163，S-N方法：平均值64，范围47-93）。先前的研究表明，其他7名LCATase缺陷受试者没有检测到LCATase活性。我们的结论是，家族性LCAT酶缺乏症在这四个挪威kinases是由于存在低水平的功能缺陷的酶。
Lecithin‐cholesterol acyltransferase (LCATase) mass was measured by radioimmunoassay in four Norwegian families with LCATase deficiency. LCATase activity was measured in some family members by the Glomset‐Wright method (G‐W method) and the Stokke‐Norum radioassay technique (S‐N method). It was also measured in one of the families by a sensitive common synthetic substrate method using apoprotein A–I‐containing proteolipo‐somes. The ten obligate heterozygotes had LCATase levels of 3.4±0.5 μg/ml (range 2.8–4.0), approximately 55–80% of the mean value of eight control subjects sampled at the same time (5.0±0.7 μg/ml, range 4.2–5.8). Six presumed heterozygotes deduced from the linkage of LCATase deficient gene with the α‐haptoglobin gene, had LCATase levels of 3.2±0.6, approximately 50–80% of control values. The eight subjects with LCATase deficiency had LCATase mass of 1.0±0.2 μg/ml (range 0.5–1.3), approximately 10–25% of control levels. The single LCATase deficient subject whose enzyme activity was measured by the synthetic substrate method had LCATase activity of 3.6 nmol/(ml·h), less than 4% of the activity level of normal subjects, 100 nmol/(ml·h), whereas the three obligate heterozygotes had LCATase activities of 48, 54, and 64 nmol/(ml·h), approximately 50–60% of the normal level. LCATase activity measured in heterozygotes by the G‐W method (mean 64, range 55–77 nmol/(ml·h),n= 6) or by the S‐N method (mean 44, range 34–67,n= 11) was significantly lower than in 30 control subjects (G‐W method: mean 120, range 91–163, S‐N method: mean 64, range 47–93). Previous studies have indicated that the seven other LCATase‐deficient subjects had no detectable LCATase activity. We conclude that familial LCATase deficiency in these four Norwegian kindreds is due to the presence of low levels of a functionally defective enzyme.