Protein–polymer hybrids are used in a variety of fields including catalysis, detection, and therapeutics. The grafting-from method for the synthesis of these biohybrids has gained popularity due to the ease of synthesis and purification. In this method, an initiator or chain transfer agent (CTA) is ligated onto an amino acid residue, typically lysine or cysteine, and polymers are subsequently grown in situ. In this manuscript, we report the preparation of protein polymer hybrids by grafting-from a previously overlooked acidic amino acid residue (glutamic and aspartic acid) and compare our results to protein polymer hybrids, grafted from the traditional lysine residue. Herein, we conjugated an atom transfer radical polymerization (ATRP) initiator to acidic amino acid residues and lysine residues and grew polymers from Thermomyces lanuginosa lipase (TL). N-[3-(N,N-Dimethylamino)propyl] acrylamide was grafted from the TL initiator, and the enzymatic activity of protein polymer hybrids was compared. We found that the acidic residues are easily modified with multiple ATRP initiators and polymers are readily grown. Additionally, the hybrids grafted from acidic residues demonstrated a 50% increase in enzyme activity compared to those grafted from lysine residues. Moreover, the activity was higher than that of native lipase TL in both cases. The polymers that were grafted-from the acid residues tended to provide the hybrids with a higher activity at elevated temperatures. These results point to a new amino acid ligation strategy for preparing protein polymer hybrids via a grafting-from method.

中文翻译：

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从脂肪酶嫁接：利用常见的氨基酸残基作为新的嫁接位点†

蛋白质-聚合物杂化物被用于多种领域，包括催化，检测和治疗。由于合成和纯化的简便性，用于合成这些生物杂化物的接枝方法已获得普及。在这种方法中，将引发剂或链转移剂（CTA）连接到氨基酸残基（通常是赖氨酸或半胱氨酸）上，然后在原位生长聚合物。在这份手稿中，我们报告了通过嫁接制备蛋白质聚合物杂种的方法-从以前被忽视的酸性氨基酸残基（谷氨酸和天冬氨酸）开始，并将我们的结果与从传统赖氨酸残基嫁接的蛋白质聚合物杂种进行了比较。在本文中，我们将原子转移自由基聚合（ATRP）引发剂与酸性氨基酸残基和赖氨酸残基共轭，并从Thermomyces lanuginosa脂肪酶（TL）中生长出聚合物。N- [3-（N，N从TL引发剂接枝了[-二甲基氨基）丙基]丙烯酰胺，并比较了蛋白质聚合物杂化物的酶活性。我们发现，酸性残基容易被多种ATRP引发剂修饰，并且聚合物易于生长。另外，与从赖氨酸残基嫁接的那些相比，从酸性残基嫁接的杂种显示出酶活性提高了50％。此外，在两种情况下，活性均高于天然脂肪酶TL。从酸残基接枝的聚合物倾向于在高温下为杂化物提供更高的活性。这些结果指出了一种新的氨基酸连接策略，用于通过嫁接法制备蛋白质聚合物杂种。